DD Support Board and Research Team

[DragonBear]

Does anyone know when L2 became available to retail traders?

That would've been dependent on when wide spread discount online brokers became available to retail.

Sam gave a link saying the Nasdaq cranked up L2 in 1983. Doubtful the price was cheap for retail. Just as the price to have access to the look ahead order book electronically is prohibitively expensive for retail today. Not to mention access (subscriptions) to quant trading programs to trade stock, or the dark pools for retail would be prohibitively expensive.

The only thing I've ever seen that might qualify as a "MM" signal (computer algor reaction) is if a stock is behaving extremely volatile, one will see a bid/ask of 1 share being placed on the L2 that retail sees. A potential signal as to where most of the bids or asks are in the order book at a given time. Or that's the way I interpret it.