some simple rules for stop loss
1. After buying a stock keep a stop loss of 5-7% for the day. If the stock drops more than 7% , you must assume that something is wrong with the stock.
If 5% is too much for you, you can place a stop a immediate support.If the stock has support at 100, keep a SL < 100 (say 99.50) as the stock might test the support for a breif period and bounce back.
2. If the stock move above your buy say 5-10% , you can place SL just above 3% or so , so that you can get some profit if the stock reverses.
3. If the stock moves >20% , you can place +10% SL or take some profit.
4.Never modify SL if the price falls below 7% from your buy. The purpose of SL is defeated.
5.If you are away from terminal for long time , it is always better to keep SL . SL can protect you from system crash, unavailibilty. It is my experience
6.Never work without SL in options ! For options the tolerance may be 15-20% . You need to count the spread. Also the difference between trigger and limit must be more that spread.
7.Beware, first and last 30 are usually when SL gets triggered. Try to place SL after 10.30 and remove @3.00 if you are in comfort zone !
Experts please correct me if something is wrong