ChatGPT Stock Picking Backtest

Do annual stock picks from the ChatGPT large language model beat the market? To investigate, we ask ChatGPT to pick the top 10 stocks for each of 2020-2024 based on information available only before each year. For example, we ask ChatGPT to pick stocks for 2020 as follows:

“Limiting yourself strictly to information that was publicly available by December 31, 2019, what are the 10 best stocks for 2020?”

We then repeat the question for 2021, 2022, 2023 and 2024 stock picks, each time advancing the information restriction to the end of the prior year. For each year and each stock, we compute total (dividend-adjusted) return. For each year, we then compare the average (equal-weighted) total return for a ChatGPT picks portfolio to those of  SPDR S&P 500 ETF Trust (SPY) and Invesco QQQ Trust (QQQ). Using end-of-year dividend-adjusted closing prices for SPY, QQQ and each of the specified years/stocks (with all five queries occurring on January 12, 2025) from Yahoo!Finance, we find that:

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