GMOC
GMO Ultra-Short Income ETF
stock NYSE ETF

Nice! - Yeah, Vanguard breaks up their bulk trades and trickles them out so it hides in "market noise" (although I wonder if AI has been unraveling those patterns). But I'd say this just blunts it rather than blocks it. Funds stopped trying to guess what Vanguard is doing *today,* and instead focuses on what Vanguard is legally forced to do months from now. Vanguard is bound by a strict fiduciary mandate to mimic an index, their long-term asset destinations are entirely transparent via prospectus. The 401K harvesting game is essentially still the same; they just shifted from latency-based front-running to predictive structural crowding, buying up equities long before Vanguard’s shredding algorithms ever execute the trade.
The issue with the closing cross is with derivatives. Equity prices on the close are fixed, but derivatives and cross-asset markets are still active. While you cannot front-run a GMOC order at 4:00pm, you can exploit options, futures, and synthetic swaps that are priced across different physical geographies and settle on slightly different microsecond clocks. You dont have to skim the equity cross itself, the lagging derivative loops right back and directly alters the price discovery, volatility, and execution costs of the underlying stocks. This is basically the bread and butter of market makers like Jane Street.
So be it the HFT strats of the early 2000s, or quant strats of today; the game is still largely the same. Retirement accounts via indexing provide a big pool of predictable, price-insensitive liquidity that generate mechanical volatility, and Wall Street harvests it.

Nice! - Yeah, Vanguard breaks up their bulk trades and trickles them out so it hides in "market noise" (although I wonder if AI has been unraveling those patterns). But I'd say this just blunts it rather than blocks it. Funds stopped trying to guess what Vanguard is doing *today,* and instead focuses on what Vanguard is legally forced to do months from now. Vanguard is bound by a strict fiduciary mandate to mimic an index, their long-term asset destinations are entirely transparent via prospectus. The 401K harvesting game is essentially still the same; they just shifted from latency-based front-running to predictive structural crowding, buying up equities long before Vanguard’s shredding algorithms ever execute the trade.
The issue with the closing cross is with derivatives. Equity prices on the close are fixed, but derivatives and cross-asset markets are still active. While you cannot front-run a GMOC order at 4:00pm, you can exploit options, futures, and synthetic swaps that are priced across different physical geographies and settle on slightly different microsecond clocks. You dont have to skim the equity cross itself, the lagging derivative loops right back and directly alters the price discovery, volatility, and execution costs of the underlying stocks. This is basically the bread and butter of market makers like Jane Street.
So be it the HFT strats of the early 2000s, or quant strats of today; the game is still largely the same. Retirement accounts via indexing provide a big pool of predictable, price-insensitive liquidity that generate mechanical volatility, and Wall Street harvests it.