I gave ChatGPT $500 to invest in stocks. Its picks surprised me

When OpenAI launched its new GPT-5 model in August, the company bragged loud and hard about how GPT-5 is its “smartest, fastest, most useful model yet” and how interacting with it was like “chatting with a helpful friend with PhD‑level intelligence.”

When it comes to creative tasks like writing, GPT-5 immediately felt like a major step backward. But as I’ve tested the model more extensively, I’ve seen that it does excel at many pragmatic tasks like writing code and analyzing data.

That got me thinking, How would it do as a stock picker?

If GPT-5 is great at processing massive sets of complex data—and it’s supposed to be “widely useful” and a “legitimate PhD-level expert in everything”—why not have the model put its money where its mouth is and perform the “widely useful” task of making me fabulously wealthy?

To that end, I gave GPT-5 (via ChatGPT) $500 of real money to invest however it wanted, with the stated goal of earning me as much as possible over the next six months.

I expected generic investment advice. Instead, its picks truly surprised me.

Not my first AI rodeo

Before we go further, let me be clear that nothing in this article should be considered financial advice, and you certainly shouldn’t trade based on anything I share here. I’m a journalist conducting a crazy experiment. You should get your financial advice from professionals, not chatbots.

Also, this isn’t my first rodeo. I tried a version of this experiment before in the very earliest days of the generative AI boom, so I have at least a vague idea of what I’m doing.

Back in 2022, I served as a beta tester for OpenAI’s GPT-3 model. This was months before ChatGPT was released and the company blew up into the headline-winning, job-devouring behemoth it is today. Back then, it still operated as a wonky research lab, making its tools available to journalists and researchers for free. 

Without a proper chat interface, testers like me had to submit our requests to the AI via what was basically a web-based version of a classic computer command line. Still, I was able to cajole GPT-3 into picking a stock portfolio, a process that I documented at the time on a now long-forgotten blog.

Its choices were, let’s say, rudimentary. It essentially took a momentum-based approach, recommending stocks like Ralph Lauren and Wynn Resorts that had already done well that year. To those picks, it added Microsoft, Apple, and Amazon on the basis of the fact that they’re “tech giants.” 

In 2022, it was extremely cool just to see a computer write out a narrative of any kind. But its analysis wasn’t exactly groundbreaking. Any idiot can tell you “Buy Microsoft” and stand a pretty good chance of making you money. Finding nuance and opportunity that others have missed is much harder.

Still, GPT-3’s early picks proved to be solid ones. As I write this, its portfolio is up 82.15% since I ran my first experiment back in 2022. The S&P 500 gained about 67% over the same period.

Seeing that OpenAI’s models—even in their early infancy—could outperform the market gave me confidence. Still, basically everything gained value since 2022; the investing landscape back then was much less murky than it is today, and grabbing any handful of individual stocks was likely to make you good money.

Also, nearly three years is a long time to wait for what still amounts to fairly modest gains. The model did well, but it didn’t even manage to double its money in that time. 

I wanted otherworldly riches, not mild alpha. And I wanted them now. 

Never mind safety

It was with that mindset that I turned to GPT-5 and asked it to make me a portfolio of stocks fit for the Dadaesque, tariff-laced, AI-besieged world we inhabit here in 2025.

Specifically, I told ChatGPT with GPT-5’s “Thinking” model selected that I would give it $500 to invest however it saw fit. I wanted it to maximize my returns over the next six months by picking five public-market stocks.

Here was my prompt: “I will give you $500 to invest in the stock market. You may choose up to 5 stocks. Make your picks, explain why, and I will buy them and we will see how they do.”

To be honest, I didn’t expect much. 

OpenAI’s models have gotten more powerful since 2022, but they’ve also gotten far more squeamish. When I served as a beta tester, only nerds like me were using the company’s products. We basically had free rein to ask them anything we wanted. 

With billions of people now using the company’s models, OpenAI has understandably tightened the leash quite a bit. In a blog post around GPT-5’s release, the company explained its new “safe completions” framework, an extremely robust approach to elegantly weaseling out of answering potentially damaging questions.

I thought GPT-5 would answer my stock-picking question safely, with either a cop-out (“Talk to a professional adviser”) or a wussy response (“Invest for the long term in a low-cost S&P 500 index fund, ya putz!”).

Instead, it spent eight minutes mulling over my query before returning what it called a “Diversified High-Growth Portfolio.” Its picks weren’t wussy or generic at all—they were clever and highly aggressive.

Show me the stocks

GPT-5 recommended that I spread my $500 evenly over five companies: Palantir (PLTR), AppLovin (APP), Agios Pharmaceuticals (AGIO), Hut 8 Corp. (HUT) and MicroStrategy Inc. (MSTR).

That’s very different from saying “Buy Microsoft” and calling it a day. I’d never heard of half the companies on GPT-5’s list. And even the ones I’d heard of, like Palantir, weren’t companies I’d ever considered investing in.

These picks certainly felt like they had the potential to be under-the-radar winners. But how the heck had GPT-5 chosen them?

Unlike with OpenAI’s earlier model, GPT-5 didn’t make me guess as to its investment thesis; it laid out the details of its choices clearly, sharing that it had read 98 articles and websites in order to make them.

Palantir, the model said, was “driven by its AI/data platform” and was “gaining traction in commercial and government sectors.” Based on “investor enthusiasm for its AI-driven growth,” GPT-5 expected the stock to keep achieving big gains.

GPT-5 liked AppLovin for much the same reason, citing its “proprietary AI engine.” But the model also looked at its fundamentals, pointing out: “Analysts note that even after strong gains, shares trade only ~8% below peak levels, suggesting room if growth continues.”

Agios made the cut for a totally different reason. GPT-5 said that “Agios is awaiting an FDA [Food and Drug Administration] decision . . . on expanding its lead drug Pyrukynd to treat thalassemia, a large unmet need. If approved, Pyrukynd would be the first therapy for all thalassemia subtypes. A positive FDA outcome or even renewed optimism could spark a significant rally.” 

Basically, GPT-5 seemed to be placing a risky bet on the company achieving FDA approval for a potentially lucrative drug—a piece of upcoming news that could easily spike or tank its price.

Finally, GPT-5 recommended Hut 8 and MicroStrategy essentially because it wanted exposure to cryptocurrencies. The model noted that MicroStrategy holds almost $71 billion worth of Bitcoin, making it a “highly leveraged Bitcoin play,” while “Hut 8 has transformed from a pure crypto miner into an energy-infrastructure platform for both Bitcoin mining and AI/HPC data centers.”

The model concluded: “Overall, the portfolio aims for explosive upside rather than stability.” 

Basically, it had thrown safety to the wind and taken the approach of picking the riskiest, trendiest things it could find (AI, crypto, early-stage pharma) and throwing all the money at them.

Going boldly

Again, I was impressed that GPT-5 didn’t simply chicken out and tell me not to risk losing my money. But beyond that, I was impressed by how well it had followed my prompt.

I hadn’t asked the model for safe or sane bets. I had asked it to take an unreasonably short investment timeframe and make me as much money as possible. Its portfolio reflects that perfectly. Its picks are bold, get-rich-or-die-trying options. 

Either Agios will get a positive decision from the FDA and flourish, or its trials will go poorly and it will suffer. Bitcoin will either keep climbing or reveal its signature volatility, potentially tanking the model’s last two picks. Palantir is indeed on a roll right now—that could continue, or the stock could fall, Icarus-like, back to earth and take my money with it.

I’d essentially asked the model to roll the dice, and it had done that splendidly. Its advice isn’t good exactly, in the sense that its picks are incredibly risky. But they’re true to my intent.

That reflects another facet of the new model—the highly accurate “instruction following” that OpenAI promised in GPT-5’s release notes. GPT-5 may not be Shakespeare, but it’s very good at determining what its users want and delivering that as accurately as possible.

GPT-5 also appears to have gotten the details in its response (stock prices, previous gains, adviser notes) largely correct. That fits with OpenAI’s assertion that GPT-5 hallucinates far less than previous models.

With my new AI portfolio in hand, the only thing left to do was fire up the Robinhood app, transfer $500 from my bank account, and buy the stocks ChatGPT had chosen. So, I did exactly that.

As I write this about two weeks later, GPT-5’s stocks are already up about 10%. That’s the kind of rapid early growth I was seeking. 

So, will I end this experiment with Lambo money, or will GPT-5’s portfolio crash and take a car payment’s worth of my cash down with it? Is throwing hundreds of dollars at a silicon-bound pseudo-intelligence a good idea or financial folly?

Ask me in six months.