If it is a forward split then the day before the split you can buy it up until. The next day the stock will trade post-split. So if it is a 10:1 ratio, you will get 10 shares for every one you own, but the price will be divided by 10. So if you had 100 shares of xyz at $10 you would have 1000 at a buck after the split. If it was a spinoff dividend then you would have to own it by the record date, but in this case the way you explained it, it sounds like it is a forward split. On a forward split you can buy it up until the day before the split. If it is a forward split you are fine.