It is well known that one of the best services a retail broker can provide is not answering the phones during a crash. The market is down, the customers panic, their timing is terrible, they want to sell at the bottom, they call you up to say “sell everything,” you say “we’re sorry all our representatives are assisting other customers, your call is important to us,” they hang up and get distracted, the market rallies, they forget about selling, you have saved them a fortune, good work. I don’t think any retail broker has this as an official policy; it seems legally dicey and hard to pull off in practice. (What if customers want to buy the dip? What if they want to sell, and you stop them, but they were right and the market keeps going down?) Also I am not sure it has much marketing appeal; people who are doing frequent single-stock trades with a retail broker presumably don’t want to be told to stop trading.
Still it seems like something to aspire to. A lot of retail financial advisers say that their job is to keep investors calm, to reassure them in turbulent markets so that they don’t dump all of their stocks at the worst possible time. If you could scale and automate that—if you could notice the worst possible time to sell stocks and then prevent customers from selling automatically, quietly, by omission—then that would be valuable. Or consider Cliff Asness’s argument that illiquid assets might actually trade at a premium, because “many investors actually realize that this accurate and timely information will make them worse investors as they’ll use that liquidity to panic and redeem at the worst times.” If you could offer selective illiquidity—“when you are probably panicking, we probably won’t answer the phone”—then rational (or, rather, rational-about-their-irrationality) investors should be willing to pay you for it.
