The SEC declining to approve some investment vehicle is not unusual at all. Compare that to the USD, where nothing short of global nuclear war is going to cause a 10-minute 25% swing.
Yes, there were in fact $4/gallon, $5/gallon, and even $8/gallon gasoline and diesel prices posted, many by noon. This also increased the price of everything shipped by truck for a while, too.
Prices came off that peak quickly, but took months to years to revert completely.
[1] - https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=E...
The price of a christmas tree drops precipitously the ~9PM on christmas eve every year, that says nothing about the value of a dollar.
Not saying that's what did or didn't happen on 9/11, though.
If I charge $1000 to eat a cracker from my cupboard, the value of a dollar didn't suddenly decrease by 99.99%.