Jane Street "slashed" Bitcoin ETF holdings 71% here's why that headline is almost certainly misleading

The narrative going around today: Jane Street is dumping Bitcoin. The reality is more interesting.

**What a 13F filing actually is:**

A 13F is a quarterly SEC disclosure that shows institutional long positions. It does not include short positions, futures contracts, options, swaps, or any other derivatives. For a passive fund, this gives you a clean picture. For a market maker? It's half the story.

Jane Street is not a passive fund. They are one of the largest and most sophisticated quantitative trading firms in the world — known for running arbitrage strategies across every major asset class at massive scale.

**What basis trading looks like on a 13F:**

Basis trade = Buy spot ETF (appears in 13F as a long position) + Sell BTC futures simultaneously (does NOT appear in 13F)

When the futures premium compresses — meaning the spread between spot and futures narrows — the firm exits the s...