NG rollover

I rolled over 1 June NG to 1 Aug NG.

I normally just sell at market and buy at market, but this time I tried to time by selling June contract and wait to see if it drops down a bit so that I could buy at a lower price. Stupid me, it started going back up before I bought the Aug contract, so by the time I bought it there was a gap of $100. Had I bought immediately, I could have saved $100. Lessons learned.

Sold 1 June NG at 2.650
Bought 1 Aug NG at 2.763