The price of any ETFs may sometimes get out of sync with the NAV/underlyings, especially on leveraged ETFs, but mainly after-hours when ETFs get rebalanced.
This happened on much larger scale with XIV and SVXY last year when they almost disappeared off the face of the planet, especially after being adjusted the next morning. I think that no one still knows their true value the night before that happened.
So with any leveraged ETFs it could be more likely that the price was “wrong” the night before and then adjusted to be correct in the morning.
Also, let’s say that SQQQ was a bit too expensive, possibly you could arbitrage it by shorting it and buying some larger value of ES futures. While you simply shorted SQQQ as a directional bet, which could go either way based on the market move, so even if the price was “wrong” you somewhat lucked out by the market not moving against you.
Also, the price movement pre-market seemed pretty smooth, indicating market makers doing their job, except the opening price at 4am was $39.39 and dropped $38.42 within a minute, so anything over $39 could’ve been mispriced.
I’d say a bit of luck might’ve played a role, but on another hand people who pay attention and analyze what/how/why stuff happens are more likely to find actual arbitrage situations
