What An Inverted Yield Curve Means For Investors
The yield spread between 10-year and 2-year US Treasury bonds has fallen below 0.2 percent, its lowest level since March 2020. A flattening or negative yield curve can be a bad sign for the economy.
What Is An Inverted Yield Curve?
In the yield curve, bonds of equal credit quality but different maturities are plotted. The most commonly used yield curve for US investors is a plot of 2-year and 10-year Treasury yields, which have yet to invert.
A typical yield curve has higher interest rates for future maturities. In a flat yield curve, short-term and long-term yields are similar. Inverted yield curves occur when short-term yields exceed long-term yields. Inversions of yield curves have historically occurred during recessions.
Inverted yield curves have preceded each of the past eight US recessions. The good news is they're far leading indicators, meaning a recession is likely not imminent.
Every US recession since 1955 has occurred between six and 24 months after an inversion of the two-year and 10-year Treasury yield curves, according to the San Francisco Fed. So, six months before COVID-19, the yield curve inverted in August 2019.
Looking Ahead
The spread between two-year and 10-year Treasury yields was 0.18 percent on Tuesday, the smallest since before the last US recession. If the graph above continues, a two-year/10-year yield curve inversion could occur within the next few months.
According to Bank of America analyst Stephen Suttmeier, the S&P 500 typically peaks six to seven months after the 2s-10s yield curve inverts, and the US economy enters recession six to seven months later.
Investors appear unconcerned about the flattening yield curve. This is in contrast to the iShares 20+ Year Treasury Bond ETF TLT +2.19% which was down 1% on Tuesday.
Inversion of the yield curve and rising interest rates have historically harmed stocks. Recessions in the US have historically coincided with or followed the end of a Federal Reserve rate hike cycle, not the start.
More on Economics & Investing
Ben Carlson
3 years ago
Bear market duration and how to invest during one
Bear markets don't last forever, but that's hard to remember. Jamie Cullen's illustration
A bear market is a 20% decline from peak to trough in stock prices.
The S&P 500 was down 24% from its January highs at its low point this year. Bear market.
The U.S. stock market has had 13 bear markets since WWII (including the current one). Previous 12 bear markets averaged –32.7% losses. From peak to trough, the stock market averaged 12 months. The average time from bottom to peak was 21 months.
In the past seven decades, a bear market roundtrip to breakeven has averaged less than three years.
Long-term averages can vary widely, as with all historical market data. Investors can learn from past market crashes.
Historical bear markets offer lessons.
Bear market duration
A bear market can cost investors money and time. Most of the pain comes from stock market declines, but bear markets can be long.
Here are the longest U.S. stock bear markets since World war 2:
Stock market crashes can make it difficult to break even. After the 2008 financial crisis, the stock market took 4.5 years to recover. After the dotcom bubble burst, it took seven years to break even.
The longer you're underwater in the market, the more suffering you'll experience, according to research. Suffering can lead to selling at the wrong time.
Bear markets require patience because stocks can take a long time to recover.
Stock crash recovery
Bear markets can end quickly. The Corona Crash in early 2020 is an example.
The S&P 500 fell 34% in 23 trading sessions, the fastest bear market from a high in 90 years. The entire crash lasted one month. Stocks broke even six months after bottoming. Stocks rose 100% from those lows in 15 months.
Seven bear markets have lasted two years or less since 1945.
The 2020 recovery was an outlier, but four other bear markets have made investors whole within 18 months.
During a bear market, you don't know if it will end quickly or feel like death by a thousand cuts.
Recessions vs. bear markets
Many people believe the U.S. economy is in or heading for a recession.
I agree. Four-decade high inflation. Since 1945, inflation has exceeded 5% nine times. Each inflationary spike caused a recession. Only slowing economic demand seems to stop price spikes.
This could happen again. Stocks seem to be pricing in a recession.
Recessions almost always cause a bear market, but a bear market doesn't always equal a recession. In 1946, the stock market fell 27% without a recession in sight. Without an economic slowdown, the stock market fell 22% in 1966. Black Monday in 1987 was the most famous stock market crash without a recession. Stocks fell 30% in less than a week. Many believed the stock market signaled a depression. The crash caused no slowdown.
Economic cycles are hard to predict. Even Wall Street makes mistakes.
Bears vs. bulls
Bear markets for U.S. stocks always end. Every stock market crash in U.S. history has been followed by new all-time highs.
How should investors view the recession? Investing risk is subjective.
You don't have as long to wait out a bear market if you're retired or nearing retirement. Diversification and liquidity help investors with limited time or income. Cash and short-term bonds drag down long-term returns but can ensure short-term spending.
Young people with years or decades ahead of them should view this bear market as an opportunity. Stock market crashes are good for net savers in the future. They let you buy cheap stocks with high dividend yields.
You need discipline, patience, and planning to buy stocks when it doesn't feel right.
Bear markets aren't fun because no one likes seeing their portfolio fall. But stock market downturns are a feature, not a bug. If stocks never crashed, they wouldn't offer such great long-term returns.
Ray Dalio
3 years ago
The latest “bubble indicator” readings.
As you know, I like to turn my intuition into decision rules (principles) that can be back-tested and automated to create a portfolio of alpha bets. I use one for bubbles. Having seen many bubbles in my 50+ years of investing, I described what makes a bubble and how to identify them in markets—not just stocks.
A bubble market has a high degree of the following:
- High prices compared to traditional values (e.g., by taking the present value of their cash flows for the duration of the asset and comparing it with their interest rates).
- Conditons incompatible with long-term growth (e.g., extrapolating past revenue and earnings growth rates late in the cycle).
- Many new and inexperienced buyers were drawn in by the perceived hot market.
- Broad bullish sentiment.
- Debt financing a large portion of purchases.
- Lots of forward and speculative purchases to profit from price rises (e.g., inventories that are more than needed, contracted forward purchases, etc.).
I use these criteria to assess all markets for bubbles. I have periodically shown you these for stocks and the stock market.
What Was Shown in January Versus Now
I will first describe the picture in words, then show it in charts, and compare it to the last update in January.
As of January, the bubble indicator showed that a) the US equity market was in a moderate bubble, but not an extreme one (ie., 70 percent of way toward the highest bubble, which occurred in the late 1990s and late 1920s), and b) the emerging tech companies (ie. As well, the unprecedented flood of liquidity post-COVID financed other bubbly behavior (e.g. SPACs, IPO boom, big pickup in options activity), making things bubbly. I showed which stocks were in bubbles and created an index of those stocks, which I call “bubble stocks.”
Those bubble stocks have popped. They fell by a third last year, while the S&P 500 remained flat. In light of these and other market developments, it is not necessarily true that now is a good time to buy emerging tech stocks.
The fact that they aren't at a bubble extreme doesn't mean they are safe or that it's a good time to get long. Our metrics still show that US stocks are overvalued. Once popped, bubbles tend to overcorrect to the downside rather than settle at “normal” prices.
The following charts paint the picture. The first shows the US equity market bubble gauge/indicator going back to 1900, currently at the 40% percentile. The charts also zoom in on the gauge in recent years, as well as the late 1920s and late 1990s bubbles (during both of these cases the gauge reached 100 percent ).
The chart below depicts the average bubble gauge for the most bubbly companies in 2020. Those readings are down significantly.
The charts below compare the performance of a basket of emerging tech bubble stocks to the S&P 500. Prices have fallen noticeably, giving up most of their post-COVID gains.
The following charts show the price action of the bubble slice today and in the 1920s and 1990s. These charts show the same market dynamics and two key indicators. These are just two examples of how a lot of debt financing stock ownership coupled with a tightening typically leads to a bubble popping.
Everything driving the bubbles in this market segment is classic—the same drivers that drove the 1920s bubble and the 1990s bubble. For instance, in the last couple months, it was how tightening can act to prick the bubble. Review this case study of the 1920s stock bubble (starting on page 49) from my book Principles for Navigating Big Debt Crises to grasp these dynamics.
The following charts show the components of the US stock market bubble gauge. Since this is a proprietary indicator, I will only show you some of the sub-aggregate readings and some indicators.
Each of these six influences is measured using a number of stats. This is how I approach the stock market. These gauges are combined into aggregate indices by security and then for the market as a whole. The table below shows the current readings of these US equity market indicators. It compares current conditions for US equities to historical conditions. These readings suggest that we’re out of a bubble.
1. How High Are Prices Relatively?
This price gauge for US equities is currently around the 50th percentile.
2. Is price reduction unsustainable?
This measure calculates the earnings growth rate required to outperform bonds. This is calculated by adding up the readings of individual securities. This indicator is currently near the 60th percentile for the overall market, higher than some of our other readings. Profit growth discounted in stocks remains high.
Even more so in the US software sector. Analysts' earnings growth expectations for this sector have slowed, but remain high historically. P/Es have reversed COVID gains but remain high historical.
3. How many new buyers (i.e., non-existing buyers) entered the market?
Expansion of new entrants is often indicative of a bubble. According to historical accounts, this was true in the 1990s equity bubble and the 1929 bubble (though our data for this and other gauges doesn't go back that far). A flood of new retail investors into popular stocks, which by other measures appeared to be in a bubble, pushed this gauge above the 90% mark in 2020. The pace of retail activity in the markets has recently slowed to pre-COVID levels.
4. How Broadly Bullish Is Sentiment?
The more people who have invested, the less resources they have to keep investing, and the more likely they are to sell. Market sentiment is now significantly negative.
5. Are Purchases Being Financed by High Leverage?
Leveraged purchases weaken the buying foundation and expose it to forced selling in a downturn. The leverage gauge, which considers option positions as a form of leverage, is now around the 50% mark.
6. To What Extent Have Buyers Made Exceptionally Extended Forward Purchases?
Looking at future purchases can help assess whether expectations have become overly optimistic. This indicator is particularly useful in commodity and real estate markets, where forward purchases are most obvious. In the equity markets, I look at indicators like capital expenditure, or how much businesses (and governments) invest in infrastructure, factories, etc. It reflects whether businesses are projecting future demand growth. Like other gauges, this one is at the 40th percentile.
What one does with it is a tactical choice. While the reversal has been significant, future earnings discounting remains high historically. In either case, bubbles tend to overcorrect (sell off more than the fundamentals suggest) rather than simply deflate. But I wanted to share these updated readings with you in light of recent market activity.
Sam Hickmann
3 years ago
Donor-Advised Fund Tax Benefits (DAF)
Giving through a donor-advised fund can be tax-efficient. Using a donor-advised fund can reduce your tax liability while increasing your charitable impact.
Grow Your Donations Tax-Free.
Your DAF's charitable dollars can be invested before being distributed. Your DAF balance can grow with the market. This increases grantmaking funds. The assets of the DAF belong to the charitable sponsor, so you will not be taxed on any growth.
Avoid a Windfall Tax Year.
DAFs can help reduce tax burdens after a windfall like an inheritance, business sale, or strong market returns. Contributions to your DAF are immediately tax deductible, lowering your taxable income. With DAFs, you can effectively pre-fund years of giving with assets from a single high-income event.
Make a contribution to reduce or eliminate capital gains.
One of the most common ways to fund a DAF is by gifting publicly traded securities. Securities held for more than a year can be donated at fair market value and are not subject to capital gains tax. If a donor liquidates assets and then donates the proceeds to their DAF, capital gains tax reduces the amount available for philanthropy. Gifts of appreciated securities, mutual funds, real estate, and other assets are immediately tax deductible up to 30% of Adjusted gross income (AGI), with a five-year carry-forward for gifts that exceed AGI limits.
Using Appreciated Stock as a Gift
Donating appreciated stock directly to a DAF rather than liquidating it and donating the proceeds reduces philanthropists' tax liability by eliminating capital gains tax and lowering marginal income tax.
In the example below, a donor has $100,000 in long-term appreciated stock with a cost basis of $10,000:
Using a DAF would allow this donor to give more to charity while paying less taxes. This strategy often allows donors to give more than 20% more to their favorite causes.
For illustration purposes, this hypothetical example assumes a 35% income tax rate. All realized gains are subject to the federal long-term capital gains tax of 20% and the 3.8% Medicare surtax. No other state taxes are considered.
The information provided here is general and educational in nature. It is not intended to be, nor should it be construed as, legal or tax advice. NPT does not provide legal or tax advice. Furthermore, the content provided here is related to taxation at the federal level only. NPT strongly encourages you to consult with your tax advisor or attorney before making charitable contributions.
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The woman
3 years ago
Because he worked on his side projects during working hours, my junior was fired and sued.
Many developers do it, but I don't approve.
Aren't many programmers part-time? Many work full-time but also freelance. If the job agreement allows it, I see no problem.
Tech businesses' policies vary. I have a friend in Google, Germany. According to his contract, he couldn't do an outside job. Google owns any code he writes while employed.
I was shocked. Later, I found that different Google regions have different policies.
A corporation can normally establish any agreement before hiring you. They're negotiable. When there's no agreement, state law may apply. In court, law isn't so simple.
I won't delve into legal details. Instead, let’s talk about the incident.
How he was discovered
In one month, he missed two deadlines. His boss was frustrated because the assignment wasn't difficult to miss twice. When a team can't finish work on time, they all earn bad grades.
He annoyed the whole team. One team member (anonymous) told the project manager he worked on side projects during office hours. He may have missed deadlines because of this.
The project manager was furious. He needed evidence. The manager caught him within a week. The manager told higher-ups immediately.
The company wanted to set an example
Management could terminate him and settle the problem. But the company wanted to set an example for those developers who breached the regulation.
Because dismissal isn't enough. Every organization invests heavily in developer hiring. If developers depart or are fired after a few months, the company suffers.
The developer spent 10 months there. The employer sacked him and demanded ten months' pay. Or they'd sue him.
It was illegal and unethical. The youngster paid the fine and left the company quietly to protect his career.
Right or wrong?
Is the developer's behavior acceptable? Let's discuss developer malpractice.
During office hours, may developers work on other projects? If they're bored during office hours, they might not. Check the employment contract or state law.
If there's no employment clause, check country/state law. Because you can't justify breaking the law. Always. Most employers own their employees' work hours unless it's a contractual position.
If the company agrees, it's fine.
I also oppose companies that force developers to work overtime without pay.
Most states and countries have laws that help companies and workers. Law supports employers in this case. If any of the following are true, the company/employer owns the IP under California law.
using the business's resources
any equipment, including a laptop used for business.
company's mobile device.
offices of the company.
business time as well. This is crucial. Because this occurred in the instance of my junior.
Company resources are dangerous. Because your company may own the product's IP. If you have seen the TV show Silicon Valley, you have seen a similar situation there, right?
Conclusion
Simple rule. I avoid big side projects. I work on my laptop on weekends for side projects. I'm safe. But I also know that my company might not be happy with that.
As an employee, I suppose I can. I can make side money. I won't promote it, but I'll respect their time, resources, and task. I also sometimes work extra time to finish my company’s deadlines.
Sanjay Priyadarshi
3 years ago
A 19-year-old dropped out of college to build a $2,300,000,000 company in 2 years.
His success was unforeseeable.
2014 saw Facebook's $2.3 billion purchase of Oculus VR.
19-year-old Palmer Luckey founded Oculus. He quit journalism school. His parents worried about his college dropout.
Facebook bought Oculus VR in less than 2 years.
Palmer Luckey started Anduril Industries. Palmer has raised $385 million with Anduril.
The Oculus journey began in a trailer
Palmer Luckey, 19, owned the trailer.
Luckey had his trailer customized. The trailer had all six of Luckey's screens. In the trailer's remaining area, Luckey conducted hardware tests.
At 16, he became obsessed with virtual reality. Virtual reality was rare at the time.
Luckey didn't know about VR when he started.
Previously, he liked "portabilizing" mods. Hacking ancient game consoles into handhelds.
In his city, fewer portabilizers actively traded.
Luckey started "ModRetro" for other portabilizers. Luckey was exposed to VR headsets online.
Luckey:
“Man, ModRetro days were the best.”
Palmer Luckey used VR headsets for three years. His design had 50 prototypes.
Luckey used to work at the Long Beach Sailing Center for minimum salary, servicing diesel engines and cleaning boats.
Luckey worked in a USC Institute for Creative Technologies mixed reality lab in July 2011. (ICT).
Luckey cleaned the lab, did reports, and helped other students with VR projects.
Luckey's lab job was dull.
Luckey chose to work in the lab because he wanted to engage with like-minded folks.
By 2012, Luckey had a prototype he hoped to share globally. He made cheaper headsets than others.
Luckey wanted to sell an easy-to-assemble virtual reality kit on Kickstarter.
He realized he needed a corporation to do these sales legally. He started looking for names. "Virtuality," "virtual," and "VR" are all taken.
Hence, Oculus.
If Luckey sold a hundred prototypes, he would be thrilled since it would boost his future possibilities.
John Carmack, legendary game designer
Carmack has liked sci-fi and fantasy since infancy.
Carmack loved imagining intricate gaming worlds.
His interest in programming and computer science grew with age.
He liked graphics. He liked how mismatching 0 and 1 might create new colors and visuals.
Carmack played computer games as a teen. He created Shadowforge in high school.
He founded Id software in 1991. When Carmack created id software, console games were the best-sellers.
Old computer games have weak graphics. John Carmack and id software developed "adaptive tile refresh."
This technique smoothed PC game scrolling. id software launched 3-D, Quake, and Doom using "adaptive tile refresh."
These games made John Carmack a gaming star. Later, he sold Id software to ZeniMax Media.
How Palmer Luckey met Carmack
In 2011, Carmack was thinking a lot about 3-D space and virtual reality.
He was underwhelmed by the greatest HMD on the market. Because of their flimsiness and latency.
His disappointment was partly due to the view (FOV). Best HMD had 40-degree field of view.
Poor. The best VR headset is useless with a 40-degree FOV.
Carmack intended to show the press Doom 3 in VR. He explored VR headsets and internet groups for this reason.
Carmack identified a VR enthusiast in the comments section of "LEEP on the Cheap." "PalmerTech" was the name.
Carmack approached PalmerTech about his prototype. He told Luckey about his VR demos, so he wanted to see his prototype.
Carmack got a Rift prototype. Here's his May 17 tweet.
John Carmack tweeted an evaluation of the Luckey prototype.
Dan Newell, a Valve engineer, and Mick Hocking, a Sony senior director, pre-ordered Oculus Rift prototypes with Carmack's help.
Everyone praised Luckey after Carmack demoed Rift.
Palmer Luckey received a job offer from Sony.
It was a full-time position at Sony Computer Europe.
He would run Sony’s R&D lab.
The salary would be $70k.
Who is Brendan Iribe?
Brendan Iribe started early with Startups. In 2004, he and Mike Antonov founded Scaleform.
Scaleform created high-performance middleware. This package allows 3D Flash games.
In 2011, Iribe sold Scaleform to Autodesk for $36 million.
How Brendan Iribe discovered Palmer Luckey.
Brendan Iribe's friend Laurent Scallie.
Laurent told Iribe about a potential opportunity.
Laurent promised Iribe VR will work this time. Laurent introduced Iribe to Luckey.
Iribe was doubtful after hearing Laurent's statements. He doubted Laurent's VR claims.
But since Laurent took the name John Carmack, Iribe thought he should look at Luckey Innovation. Iribe was hooked on virtual reality after reading Palmer Luckey stories.
He asked Scallie about Palmer Luckey.
Iribe convinced Luckey to start Oculus with him
First meeting between Palmer Luckey and Iribe.
The Iribe team wanted Luckey to feel comfortable.
Iribe sought to convince Luckey that launching a company was easy. Iribe told Luckey anyone could start a business.
Luckey told Iribe's staff he was homeschooled from childhood. Luckey took self-study courses.
Luckey had planned to launch a Kickstarter campaign and sell kits for his prototype. Many companies offered him jobs, nevertheless.
He's considering Sony's offer.
Iribe advised Luckey to stay independent and not join a firm. Iribe asked Luckey how he could raise his child better. No one sees your baby like you do?
Iribe's team pushed Luckey to stay independent and establish a software ecosystem around his device.
After conversing with Iribe, Luckey rejected every job offer and merger option.
Iribe convinced Luckey to provide an SDK for Oculus developers.
After a few months. Brendan Iribe co-founded Oculus with Palmer Luckey. Luckey trusted Iribe and his crew, so he started a corporation with him.
Crowdfunding
Brendan Iribe and Palmer Luckey launched a Kickstarter.
Gabe Newell endorsed Palmer's Kickstarter video.
Gabe Newell wants folks to trust Palmer Luckey since he's doing something fascinating and answering tough questions.
Mark Bolas and David Helgason backed Palmer Luckey's VR Kickstarter video.
Luckey introduced Oculus Rift during the Kickstarter campaign. He introduced virtual reality during press conferences.
Oculus' Kickstarter effort was a success. Palmer Luckey felt he could raise $250,000.
Oculus raised $2.4 million through Kickstarter. Palmer Luckey's virtual reality vision was well-received.
Mark Zuckerberg's Oculus discovery
Brendan Iribe and Palmer Luckey hired the right personnel after a successful Kickstarter campaign.
Oculus needs a lot of money for engineers and hardware. They needed investors' money.
Series A raised $16M.
Next, Andreessen Horowitz partner Brain Cho approached Iribe.
Cho told Iribe that Andreessen Horowitz could invest in Oculus Series B if the company solved motion sickness.
Mark Andreessen was Iribe's dream client.
Marc Andreessen and his partners gave Oculus $75 million.
Andreessen introduced Iribe to Zukerberg. Iribe and Zukerberg discussed the future of games and virtual reality by phone.
Facebook's Oculus demo
Iribe showed Zuckerberg Oculus.
Mark was hooked after using Oculus. The headset impressed him.
The whole Facebook crew who saw the demo said only one thing.
“Holy Crap!”
This surprised them all.
Mark Zuckerberg was impressed by the team's response. Mark Zuckerberg met the Oculus team five days after the demo.
First meeting Palmer Luckey.
Palmer Luckey is one of Mark's biggest supporters and loves Facebook.
Oculus Acquisition
Zuckerberg wanted Oculus.
Brendan Iribe had requested for $4 billion, but Mark wasn't interested.
Facebook bought Oculus for $2.3 billion after months of drama.
After selling his company, how does Palmer view money?
Palmer loves the freedom money gives him. Money frees him from small worries.
Money has allowed him to pursue things he wouldn't have otherwise.
“If I didn’t have money I wouldn’t have a collection of vintage military vehicles…You can have nice hobbies that keep you relaxed when you have money.”
He didn't start Oculus to generate money. His virtual reality passion spanned years.
He didn't have to lie about how virtual reality will transform everything until he needed funding.
The company's success was an unexpected bonus. He was merely passionate about a good cause.
After Oculus' $2.3 billion exit, what changed?
Palmer didn't mind being rich. He did similar things.
After Facebook bought Oculus, he moved to Silicon Valley and lived in a 12-person shared house due to high rents.
Palmer might have afforded a big mansion, but he prefers stability and doing things because he wants to, not because he has to.
“Taco Bell is never tasted so good as when you know you could afford to never eat taco bell again.”
Palmer's leadership shifted.
Palmer changed his leadership after selling Oculus.
When he launched his second company, he couldn't work on his passions.
“When you start a tech company you do it because you want to work on a technology, that is why you are interested in that space in the first place. As the company has grown, he has realized that if he is still doing optical design in the company it’s because he is being negligent about the hiring process.”
Once his startup grows, the founder's responsibilities shift. He must recruit better firm managers.
Recruiting talented people becomes the top priority. The founder must convince others of their influence.
A book that helped me write this:
The History of the Future: Oculus, Facebook, and the Revolution That Swept Virtual Reality — Blake Harris
*This post is a summary. Read the full article here.
Laura Sanders
3 years ago
Xenobots, tiny living machines, can duplicate themselves.
Strange and complex behavior of frog cell blobs
A xenobot “parent,” shaped like a hungry Pac-Man (shown in red false color), created an “offspring” xenobot (green sphere) by gathering loose frog cells in its opening.
Tiny “living machines” made of frog cells can make copies of themselves. This newly discovered renewal mechanism may help create self-renewing biological machines.
According to Kirstin Petersen, an electrical and computer engineer at Cornell University who studies groups of robots, “this is an extremely exciting breakthrough.” She says self-replicating robots are a big step toward human-free systems.
Researchers described the behavior of xenobots earlier this year (SN: 3/31/21). Small clumps of skin stem cells from frog embryos knitted themselves into small spheres and started moving. Cilia, or cellular extensions, powered the xenobots around their lab dishes.
The findings are published in the Proceedings of the National Academy of Sciences on Dec. 7. The xenobots can gather loose frog cells into spheres, which then form xenobots.
The researchers call this type of movement-induced reproduction kinematic self-replication. The study's coauthor, Douglas Blackiston of Tufts University in Medford, Massachusetts, and Harvard University, says this is typical. For example, sexual reproduction requires parental sperm and egg cells. Sometimes cells split or budded off from a parent.
“This is unique,” Blackiston says. These xenobots “find loose parts in the environment and cobble them together.” This second generation of xenobots can move like their parents, Blackiston says.
The researchers discovered that spheroid xenobots could only produce one more generation before dying out. The original xenobots' shape was predicted by an artificial intelligence program, allowing for four generations of replication.
A C shape, like an openmouthed Pac-Man, was predicted to be a more efficient progenitor. When improved xenobots were let loose in a dish, they began scooping up loose cells into their gaping “mouths,” forming more sphere-shaped bots (see image below). As many as 50 cells clumped together in the opening of a parent to form a mobile offspring. A xenobot is made up of 4,000–6,000 frog cells.
Petersen likes the Xenobots' small size. “The fact that they were able to do this at such a small scale just makes it even better,” she says. Miniature xenobots could sculpt tissues for implantation or deliver therapeutics inside the body.
Beyond the xenobots' potential jobs, the research advances an important science, says study coauthor and Tufts developmental biologist Michael Levin. The science of anticipating and controlling the outcomes of complex systems, he says.
“No one could have predicted this,” Levin says. “They regularly surprise us.” Researchers can use xenobots to test the unexpected. “This is about advancing the science of being less surprised,” Levin says.