SPY Mispriced $42 Million. Nobody cares.

When you can't trust the OG ETF, Who can you trust?

April 9th 2025 was a heck of a market day, right? Crazy whipsaw, probably insider trading, all that jazz. Seemingly lost in the shuffle is the worst closing auction — by dollar value mispricing — I’ve ever seen. And every chart or algo that includes SPY on April 9th is gonna look weird forever.

Here’s the quote:

“SPY has been synonymous with ‘ETF’ for over 25 years, and investors have come to rely on its operational predictability. The clearly-bad closing auction on April 9th 2025 created one of the largest mispricings I’ve ever seen in an ETF: $42 million in a single auction. Despite the obvious data on the tape, State Street Global Advisors continues to misrepresent the trading of SPY in this high volatility period, claiming the fund traded to a 5bps discount, rather than obviously observable 90bps premium. Trust is becoming a scarcer commodity by the market day.”
- Dave Nadig, Independent ETF Expert

First let’s just look at SPY trading on April 9th.

(Full analysis for paying subscribers below the break)