https://www.interactivebrokers.com/en/?f=/en/trading/order-handling-using-price-capping.php What about Schwab or Lightspeed?
This is a regulatory requirement to help prevent obvious errors. I think in general the rule is 7% outside regular trading hours and 10% in regular trading hours. We have no choice be to put these in place.
For orders that are routed to an exchange I think it would make a lot more sense for the exchanges to implement the price caps instead of brokers. That way every participant on the exchange would have an even playing field, and not to mention it would be way easier for brokers to be compliant.
It becomes a problem when the broker's cap calculations are screwed up and they stop you from trading for no good reason. Worst case scenario, big losses because you can't exit a position.
I’m what situation do you need to buy a stock 5% above ask? If you have a valid justification for it, you can work with compliance officer to make an exception for you. That’s why it’s up to individual broker dealer to enforce this guidelines.
You are correct. Most of the time, entering a limit 10% away from last sale is silly. The one exception is when a stock comes out of a halt. The last sale can be $10, but it might re-open at $25. Some systems will block a limit order to buy at $25. I believe on Lightspeed, we would accept a LOO order during T3, where the limit is within 10% of the T3 quote.
You don't get it. The problem is when the broker doesn't calculate the cap properly and you can't even buy at the ask. This can happen for any number of reasons; there are a ton of edge cases to handle and brokers definitely can not be trusted to get this right.