Quote from cornholetrading:
Well first the trading firm made a lot of money from them, which helped offset the squeeze from commission rates and ecn rates dropping (the line of straight passthru ECN fees was a BS line used by many firms for a long time). So this might take down the shaky firm in the business.
There are many reasons for traders upset about the ending of bullets and conversions. I know traders who have been using them for 4 or 5 years so it will totally change the way they trade which can be quite upsetting. This was especially true with the large down moves that occured for almost 2 years. Also when news comes out on a stock it will be almost impossible to get any shares that you could get if you had bullets. That can be the difference in making 2 pts on a move or making nothing. Also some traders chose to scalp trading 200-800K+ shares a day where bullets were almost necessary. So just because you never used them and got used to shorting against the momentum doesn't mean that everyone trades or wants to trade the same way you want to. If you woke up one day and found out a huge tool in your trading was just taken away you would probably be upset too. Yes you could or would possibly adapt but it would still probably make you mad and a little bit nervous.