I think you'll be on fire! This is a bull trend right thru to the monthly chart. There's a chance of a quick pullback but with so much up pressure I'd want to see it signal intraday and then short it, but to short it on a double top with this much strength risks a blow through gap opening. It's just broken up through a rising wedge with a wide range candle on big volume. If that wedge formation was not broken then the shorts would look good and the volume would signal a reversal. As the formation has a bullish break and the weekly and monthly timeframes are very bullish you should have been positioned long waiting for a reversal signal. You are trading on anticipation of a reversal but there a good chance of a gap up. This can be an easy low risk short if you take the position on an intraday reversal signal. Going short at 36 in a bull trend was a mistake but adding at 40 double top is a real gamble. I've read some of your posts and you do good work. IMHO you have not distinguished between a good double top for shorting and one that is likely to blow through. Also this is the 3rd attempt at this level daily. The 2nd had a volume failure. This attempt has greater volume than that failure and so tells you to wait for a reversal signal as the pressure up is greater. Good luck, you might need it.
SYNA's a great intraday short, but I agree too soon for anything longer term, because of the gap risk.