1dte ATM SPY straddles

So basically what this is a trend of profitability I’ve seen. But I’m wondering if it’s just a symptom of the current(since 2020) irrationality of the market or just a function of the value of stocks being high generally. So I’ve noticed that even if you aren’t predicting price movements. Buying a straddle at whatever closing price for SPY is in the 15 minutes after market window closes. IE close is $740.83 you buy a $741 straddle at 4:05-4:10pm ET. Then you generally try to sell in the 10-11:30am window the next day. Since theta decay is negligible and IV tends to spike early morning I’ve found on regular trading days that the losing side of the straddle tends to be covered by the winning side resulting in a net 1-15% return day over day by the time that I exit. The one thing to pay attention to is what I refer to and I’ve heard some others refer to as risk resolution events. These are things like FED meetings, elections, congressional votes, BLS reports(non-farm payrolls especially). Generally the strategy works the days leading up to these events but it loses hard the actual day of the event, I.E. the actual day of the FOMC announcement. This obviously coincides with these days being far more likely to trade flat or sub 1% move since pricing in has already occurred due to the Fed being predictable and the fact that there are a lot of firms that collect better data than the BLS. This is also a side effect of that a 1% move in SPY is generally big enough to make this cover unless the market has been crashing due to the stupid ways that black scholes calculates the premium on puts when going in a bear direction. Mostly just because of the mechanics of IV, but I digress. I’m wondering if the success of this strategy is due to underlying market truths, or just because SPY is so high that a 1% move when accounting for early morning IV is enough to make this profitable. I’ve found this to have like an 80% win rate with 90% of the losses coming on risk resolution events.