We gave 5 LLMs $100K to trade stocks for 8 months
83 comments
·December 4, 2025bcrosby95
IgorPartola
Yeah I mean if you generally believe the tech sector is going to do well because it has been doing well you will beat the overall market. The problem is that you don’t know if and when there might be a correction. But since there is this one segment of the overall market that has this steady upwards trend and it hasn’t had a large crash, then yeah any pattern seeking system will identify “hey this line keeps going up!” Would it have the nuance to know when a crash is coming if none of the data you test it on has a crash?
It would almost be more interesting to specifically train the model on half the available market data, then test it on another half. But here it’s like they added a big free loot box to the game and then said “oh wow the player found really good gear that is better than the rest!”
Edit: from what I causally remember a hedge fund can beat the market for 2-4 years but at 10 years and up their chances of beating the market go to very close to zero. Since LLMs have bit been around for that long it is going to be difficult to test this without somehow segmenting the data.
tshaddox
> It would almost be more interesting to specifically train the model on half the available market data, then test it on another half.
Yes, ideally you’d have a model trained only on data up to some date, say January 1, 2010, and then start running the agents in a simulation where you give them each day’s new data (news, stock prices, etc.) one day at a time.
olliepro
A more sound approach would have been to do a monte carlo simulation where you have 100 portfolios of each model and look at average performance.
observationist
Grok would likely have an advantage there, as well - it's got better coupling to X/Twitter, a better web search index, fewer safety guardrails in pretraining and system prompt modification that distort reality. It's easy to envision random market realities that would trigger ChatGPT or Claude into adjusting the output to be more politically correct. DeepSeek would be subject to the most pretraining distortion, but have the least distortion in practice if a random neutral host were selected.
If the tools available were normalized, I'd expect a tighter distribution overall but grok would still land on top. Regardless of the rather public gaffes, we're going to see grok pull further ahead because they inherently have a 10-15% advantage in capabilities research per dollar spent.
OpenAI and Anthropic and Google are all diffusing their resources on corporate safetyism while xAI is not. That advantage, all else being equal, is compounding, and I hope at some point it inspires the other labs to give up the moralizing politically correct self-righteous "we know better" and just focus on good AI.
I would love to see a frontier lab swarm approach, though. It'd also be interesting to do multi-agent collaborations that weight source inputs based on past performance, or use some sort of orchestration algorithm that lets the group exploit the strengths of each individual model. Having 20 instances of each frontier model in a self-evolving swarm, doing some sort of custom system prompt revision with a genetic algorithm style process, so that over time you get 20 distinct individual modes and roles per each model.
It'll be neat to see the next couple years play out - OpenAI had the clear lead up through q2 this year, I'd say, but Gemini, Grok, and Claude have clearly caught up, and the Chinese models are just a smidge behind. We live in wonderfully interesting times.
jessetemp
> fewer safety guardrails in pretraining and system prompt modification that distort reality.
Really? Isn't Grok's whole schtick that it's Elon's personal altipedia?
monksy
They're not measuring performance in the context of when things happen and in the time that they are. It think its only showing recent performance and popularity. To actually evaluate how these do you need to be able to correct the model and retrain it per different time periods and then measure how it would do. Then you'll get better information from the backtesting.
etchalon
I don't feel like they measured anything. They just confirmed that tech stocks in the US did pretty well.
JoeAltmaier
They measured the investment facility of all those LLMs. That's pretty much what the title says. And they had dramatically different outcomes. So that tells me something.
DennisP
I mean, what it kinda tells me is that people talk about tech stocks the most, so that's what was most prevalent in the training data, so that's what most of the LLMs said to invest in. That's the kind of strategy that works until it really doesn't.
dash2
There's also this thing going on right now: https://nof1.ai/leaderboard
Results are... underwhelming. All the AIs are focused on daytrading Mag7 stocks; almost all have lost money with gusto.
richardhenry
If I'm understanding this website correctly, these models can only trade in a handful of tech stocks along with the XYZ100 hyperliquid coin?
syntaxing
Let me guess, the mystery model is theirs
Nevermark
Just one run per model? That isn't backtesting. I mean technically it is, but "testing" implies producing meaningful measures.
Also just one time interval? Something as trivial as "buy AI" could do well in one interval, and given models are going to be pumped about AI, ...
100 independent runs on each model over 10 very different market behavior time intervals would producing meaningful results. Like actually credible, meaningful means and standard deviations.
This experiment, as is, is a very expensive unbalanced uncharacterizable random number generator.
cheeseblubber
Yes definitely we were using our own budget and out of our own pocket and these model runs were getting expensive. Claude costed us around 200-300 dollars a 8 month run for example. We want to scale it and get more statistically significant results but wanted to share something in the interim.
naet
I used to work for a brokerage API geared at algorithmic traders and in my experience anecdotal experience many strategies seem to work well when back-tested on paper but for various reasons can end up flopping when actually executed in the real market. Even testing a strategy in real time paper trading can end up differently than testing on the actual market where other parties are also viewing your trades and making their own responses. The post did list some potential disadvantages of backtesting, so they clearly aren't totally in the dark on it.
Deepseek did not sell anything, but did well with holding a lot of tech stocks. I think that can be a bit of a risky strategy with everything in one sector, but it has been a successful one recently so not surprising that it performed well. Seems like they only get to "trade" once per day, near the market close, so it's not really a real time ingesting of data and making decisions based on that.
What would really be interesting is if one of the LLMs switched their strategy to another sector at an appropriate time. Very hard to do but very impressive if done correctly. I didn't see that anywhere but I also didn't look deeply at every single trade.
cheeseblubber
OP here. We realized there are a ton of limitations with backtest and paper money but still wanted to do this experiment and share the results. By no means is this statistically significant on whether or not these models can beat the market in the long term. But wanted to give everyone a way to see how these models think about and interact with the financial markets.
irishcoffee
> But wanted to give everyone a way to see how these models think…
Think? What exactly did “it” think about?
cheeseblubber
You can click in to the chart and see the conversation as well as for each trade what was the reasoning it gave for it
stoneyhrm1
"Pass the salt? You mean pass the sodium chloride?"
apparent
> Grok ended up performing the best while DeepSeek came close to second.
I think you mean "DeepSeek came in a close second".
joegibbs
I think it would be interesting to see how it goes in a scenario where the market declines or where tech companies underperform the rest of the market. In recent history they've outperformed the market and that might bias the choices that the LLMs make - would they continue with these positive biases if they were performing badly?
null
_alternator_
Wait, they didn’t give them real money. They simulated the results.
sethops1
> Testing GPT-5, Claude, Gemini, Grok, and DeepSeek with $100K each over 8 months of backtested trading
So the results are meaningless - these LLMs have the advantage of foresight over historical data.
PTRFRLL
> We were cautious to only run after each model’s training cutoff dates for the LLM models. That way we could be sure models couldn’t have memorized market outcomes.
stusmall
Even if it is after the cut off date wouldn't the models be able to query external sources to get data that could positively impact them? If the returns were smaller I could reasonably believe it but beating the S&P500 returns by 4x+ strains credulity.
cheeseblubber
We used the LLMs API and provided custom tools like a stock ticker tool that only gave stock price information for that date of backtest for the model. We did this for news apis, technical indicator apis etc. It took quite a long time to make sure that there weren't any data leakage. The whole process took us about a month or two to build out.
plufz
I know very little about how the environment where they run these models look, but surely they have access to different tools like vector embeddings with more current data on various topics?
endtime
If they could "see" the future and exploit that they'd probably have much higher returns.
disconcision
you can (via the api, or to a lesser degree through the setting in the web client) determine what tools if any a model can use
itake
> We time segmented the APIs to make sure that the simulation isn’t leaking the future into the model’s context.
I wish they could explain what this actually means.
nullbound
Overall, it does sound weird. On the one hand, assuming I properly I understand what they are saying is that they removed model's ability to cheat based on their specific training. And I do get that nuance ablation is a thing, but this is not what they are discussing there. They are only removing one avenue of the model to 'cheat'. For all we know, some that data may have been part of its training set already...
devmor
It's a very silly way of saying that the data the LLMs had access to was presented in chronological order, so that for instance, when they were trading on stocks at the start of the 8 month window, the LLMs could not just query their APIs to see the data from the end of the 8 month window.
joegibbs
That's only if they're trained on data more recent than 8 months ago
copypaper
>Each model gets access to market data, news APIs, company financials...
The article is very very vague on their methodology (unless I missed it somewhere else?). All I read was, "we gave AI access to market data and forced it to make trades". How often did these models run? Once a day? In a loop continuously? Did it have access to indicators (such as RSI)? Could it do arbitrary calculations with raw data? Etc...
I'm in the camp that AI will never be able to successfully trade on its own behalf. I know a couple of successful traders (and many unsuccessful!), and it took them years of learning and understanding before breaking even. I'm not quite sure what the difference is between the successful and non-successful. Some sort of subconscious knowledge from staring at charts all day? A level of intuition? Regardless, it's more than just market data and news.
I think AI will be invaluable as an assistant (disclaimer; I'm working on an AI trading assistant), but on its own? Never. Some things simply simply can't be solved with AI and I think this is one of them. I'm open to being wrong, but nothing has convinced me otherwise.
cedws
Backtesting for 8 months is not rigorous enough and also this site has no source code or detailed methodology. Not worth the click.
buredoranna
Like so many analyses before them, including my own, this completely misses the basics of mean/variance risk analysis.
We need to know the risk adjusted return, not just the return.
swatcoder
What were the hypotheses being tested in this "experiment"? What conclusions did the experimenters draw from their findings? If this experiment was repeated, would do the experimenters think the outcomes would be comparable?
This seems entirely like trivial social media bait and nothing like research: "We gave each major LLM and stock trading prompt. You won't believe which performed best!"
mlmonkey
> We were cautious to only run after each model’s training cutoff dates for the LLM models
Grok is constantly training and/or it has access to websearch internally.
You cannot backtest LLMs. You can only "live" test them going forward.
cheeseblubber
Via api you can turn off websearch internally. We provided all the models with their own custom tools that only provided data up to the date of the backtest.
mlmonkey
But Grok is internally training on Tweets etc. continuously.
> Grok ended up performing the best while DeepSeek came close to second. Almost all the models had a tech-heavy portfolio which led them to do well. Gemini ended up in last place since it was the only one that had a large portfolio of non-tech stocks.
I'm not an investor or researcher, but this triggers my spidey sense... it seems to imply they aren't measuring what they think they are.