GameStop. The fortnight a subreddit executed the most public short squeeze in market history and every system this archive tracks, market microstructure, platform incentives, mob coordination, clearing-house plumbing, collided in one ticker. The mechanics, filed properly: WallStreetBets identified that GameStop was shorted beyond 100% of its float (an over-leveraged position visible in public data), coordinated a buy-and-hold spiral with meme-grade conviction (“diamond hands,” rocket emojis as consensus protocol), and drove the stock from ~$20 to an intraday ~$483, detonating a hedge fund (Melvin, bailed out mid-squeeze) and briefly making the joke stock worth more than half the S&P’s members. Then the infrastructure spoke: Robinhood, the retail platform whose whole brand was democratized access, restricted buying (sell-only) at the squeeze’s peak, and the conspiracy theories wrote themselves until the mundane truth emerged, which this blog appreciated alone in a crowd screaming about villains: clearing-house collateral requirements. Two-day settlement (T+2) means Robinhood fronts risk on every trade for 48 hours; the volatility spiked their deposit requirement tenfold overnight (a multi-billion-dollar margin call at 5am); and restricting buys was the position-limiting move available. The plumbing nobody knew existed became the story everyone got wrong (the old oil-contango lesson: the price is a fact about the mechanism, and the mechanism has capacity limits, always, everywhere, forever).
The aftermath queue: congressional hearings scheduled, T+1 settlement suddenly on the industry roadmap (a decade of “someday” converted to “soon” by one week of memes, incidents drive modernization), and the deeper file: coordination costs collapsed (a million retail traders synchronized for free via memes, the positional-leverage doctrine, now retail-shaped), while payment-for-order-flow’s conflicts got their first mainstream vocabulary lesson. Nobody in the stack was neutral; everyone’s incentives were suddenly legible. The market survived being understood, barely.
TIL: T+2 settlement and NSCC deposit formulas, the actual math of why the buying stopped. The most important system is always the one you learn exists during its worst week (the archive’s entire epistemology in one pattern).