Uncertainty based on incomplete data. With an investment, you have most of the data about a given venture as it stands at the moment in front of you; only the f

Uncertainty based on incomplete data. With an investment, you have most of the data about a given venture as it stands at the moment in front of you; only the future is uncertain. With a gamble, you have profoundly incomplete information about the venture in its present state. This is often a feature for the "house", who can use this information asymmetry to manipulate odds. $300 wasn't gambling if you were throwing in based on an understanding of gamma and short squeezes and GME's standing on the week of the 25th. That information was complete and supported the thesis, "If I buy at $300/share I should be able to sell at a profit in the near future." (And,this turned out to be correct; selling before trading opened would have netted an up yo 65% return.) It was, however, ultimately a gamble, because of incomplete information about the solvency of retail brokerages (and the ability of "the house" to manipulate odds by increasing collateral requirements without explanation). Unfortunately, this revelation marks the entire financial market as essentially a casino.