Ann: Bidders and Targets Statements Mailed Out,GMM-GXY.AX, page-37

What's the cut-off date for acceptance. Presumably, you can buy right up to that point if the share is trading freely, then submit your acceptance, but you run the risk of trading halts etc. getting in your way. Shares become rarer as they are transitioned across, with less freely trading one would think, this could have the effect of pushing the share price upward, making it LESS attractive depending on the share ratios on the day.

Really, this is splitting hairs. Buy GMM (then Accept the merger), or buy GXY, either way you're making a good choice...