If you examine the question you asked carefully, you'll see that you are actually asking two different questions.Quote from flier6:
I need some help in regards to determining if a level is holding or not in real time.
Let's say that price is trading up toward a resistance level that I think will hold and I want to get short at that level. What are the things I should be looking for before entering short?
Thanks for your help.
1. You say that you need to determine whether a level is holding or not. That means that the level has been reached - is it holding?
2. The you say 'Let's say price is trading up toward a resistance level that I think will hold'. Ah! that's different.
See that? Two subtly different things. If you're fading a move, then you're presumably entering when price touches that S/R level you've identified. In that case you can reasonably ask what to look for before entering.
I think I know what your problem is. Perhaps you enter S/R trades and you see price tick above the line you've drawn. Your stops are getting hit, only to find that the price moves in the direction you thought it would. Is that accurate? You're trying to figure out how to avoid this.
I hate to tell you this, but as valid as John's points are, there is no answer to your question. There are some trading cliches that are useless (like 'You can never go broke taking a profit'). There are some which are valuable, like 'trade what you see'.
It's all about position sizing and trade management, as much as that seems like another cliche. I'll bet you've experienced this one too - you enter, price immediately goes in your direction, then starts to retrace back to your entry point. You wonder 'How in the hell am I supposed to let this winning trade turn into a loser?'. So you blow it out with a small profit, only to see price go hard in your direction.
No way to figure this one out except by doing it over and over. There are plenty of guys who daytrade by legging in. This takes iron discipline and is not the same as averaging a loser down, since the point at which the trade is defined as a loser is not met until the full position is put on and price has breached a level based on R/R calculations at that level.