QQQ

Nasdaq-100 (Invesco QQQ Trust)

Invesco (QQQ Trust; QQQM is the cheaper sibling share class). Tracks the Nasdaq-100 — the 100 largest non-financial companies on Nasdaq, cap-weighted, maintained by Nasdaq.

The most direct 'index = the AI trade' baseline. The Nasdaq-100 excludes financials and is heavily tech-tilted, so Information Technology is ~59% of the fund (vs ~33% for the S&P 500) and the same megacap-AI names sit at even higher weights. Buying QQQ is the closest thing to a passive concentrated AI/compute bet, which is exactly why it's the benchmark active AI managers most often quote themselves against.