Quote from garbo:
Seems like some people are missing the main point of the cancel fees, which is to PROTECT market makers from Joe Trader who knows how to program.
Think about it: You're a market maker on, say, XAU options: You've got September 85 puts at 15.60 bid, 16.60 ask. Of course, there are not a lot of suckers playing your game with a spread like that. But it only takes a couple to put dinner on the table.
Now comes Joe Trader using IB's API to program option orders. He decides to undercut you and is ready to do 15.70 bid, 16.50 ask. Of course the price is constantly shifting, so the only way for him to compete is to automate (read IB API) his orders.
Now you say f**k him: Why should you have to compete? You've got a good sucker game going here (options). How do you cut him out? CANCEL FEEs, of course. If he loses nickels every time he changes his order, no way can he compete.
Naturally, the SEC is happy to go along with such crap to prevent any possible fair competition from Joe Trader (just as they were happy to sign off on the $1.4 billion slap on the wrist of Wall Street -- please stop me from ranting...)