SPY has tight (penny wide spreads) because it is fairly valued. Biggest firms in the world MM in it or use it elsewhere. Probably better to use SPY as a fair value engine and then trade a less liquid but correlated chain to gain some edge.
loop is dead. commercial buildings are completing being built (I assume from low interest loans) and they're all empty. walgreens and cvs lock everything up. marianos has multiple off duty police patrolling the isles. multiple shootings near ogilvie's new (or maybe old) homeless encampment under...
that's spoofing at a cost. there are limits to how much a bot can lose just like humans. It will turn off. However, you could use AI to read specifications to find anything advantageous.
The issuer of the etf provides the calculation on its website. Anyone can then consume constituent data and compute indicative nav. 14 years ago Etfs were never out of line. And if they appeared to be there was no liquidity. I assume it's even more efficient today
probably smaller list if you ask which brokerages do not let you fully create BOTS and utilize technical analysis to trade options (including full spreads)