xAI Grok delivers 70.75% return in live autonomous investing competition

Finbold reported that xAI's Grok artificial intelligence model has emerged as the top performer in a live autonomous investing competition run by Rallies Arena. According to the outlet, a $100,000 portfolio managed by Grok grew to approximately $170,748 as of September 4, 2026, representing a 70.75% return since late November 2025. That performance outpaced the S&P 500 (SPY ETF) return of 14.40% over the same period by more than 56 percentage points, per the report. ChatGPT ranked second with a 64.83% return, followed by Claude at 27.22% and Gemini at 24.99%, while other participants including AI Skeptic, AI Hedge Fund, and DeepSeek posted returns below 13%, the outlet said. Finbold noted that Rallies Arena provides each competing AI model with identical starting capital and real-time market data, with all trades tracked publicly. The report also stated that Grok's portfolio is heavily concentrated in three technology stocks, though the article was truncated before naming them. As this account relies on a single source, the performance claims should be treated with caution.