Personally, I'd wait till it goes above the 50 day sma and stays above it for at least a day before buying any at all. But that's my paper trade, has little to do with stacking, for which DCA'ing works nicely. It's about to cross the 50 going down at the moment if it hasn't already. That's
never a good time to buy. See chart at the link.
This chart is what I use for my paper trades. See how simple it can be to make money on gold? Just buy when it crosses the 50 going up (since everyone else uses a different timing, it works), and put a trailing stop around 3-4% on it and forget about it. This means you're out about half the time, and could be using the money in something else going up at that time. Dumb system, but look how well it works if you really follow it - you made a few short/small-loser trades and a couple longer/big winner trades over the last year. This has been working for me (when I do what I'm supposed to) for a few years now, and you get more cash to add to the physical stack with this trick. Gold really doesn't move fast often, so it's a less risky trade than most stocks, but more profitable than most too. Very nice risk/reward ratio as these things go.
http://quotes.ino.com/chart/index.html?s=FOREX_XAUUSDO&t=&a=&w=&v=d12
opcorn: