Kevi, FWIW, a poster I respect on another site says you should...

Kevi, FWIW, a poster I respect on another site says you should always try to avoid buying at open unless you are absolutely sure the price will go higher from there.

Occasionally I buy at open, as I cant resist on some stocks, but I often regret it, so I now think that as a general rule he is on the money. Looks at MOF's open today - some big bids, but a few big sellers holding back till the open.

Probably the best time to value a stock and decide whether it will move up on the day is at 20-40 minutes after the open, as you have a chance to gauge fair value, and volume compared to recent history.
However, after this multi-month sell down, stocks can rise substantially on very low volume.

a 'non-professional' opinion of course!