Oh thought you were talking eur. I'm gonna go with Serpens66 on that one, especially if your just speculating on the price, EURUSD conversion is as good as fixed rate compared to Bitcoin. If you have to trade against the spread you're going to get eaten in no time, it's 2% between bid and ask right now. So it would have to fall another 2% before you break even, and then again you may be wrong.

It's always good to 'backtest' you're strategy against historical prices. They a look at this chart (BTCEUR) : http://bitcoinwisdom.com/markets/kraken/btceur , get a calculator and see what would've happened if you did this a day, a week or a month ago, to get a feel for the profitability of your strategy. In the last month the daily difference between high and low has been more than 3% on 9 separate days, which would've surely triggered your stop. You have to keep in mind that your stop is reset any time the best bid reaches a new high, and triggered any time the best bid  3% below that. It doesn't matter if it's just for a second and for a size of 0.0001 btc.