[yieldcrv]

since I like gambling on stock exchanges and table games I prefer the more nuanced term for the specific game I'm playing.

its more wasteful for some segment of our society to need a distinction between investing or gambling at all, the people they're competing against don't care, don't have any cultural limitation, religious limitation, or peer group that needs this distinction. and your "legitimizes" wording looks based on needing a distinction.

even with the "positive or negative expected value" metrics to distinguish some financial games, I've traded options contracts with a lower expected value than a table game at a casino. so just don't worry about the distinction and use our words for the specific game we're playing. prediction markets are prediction markets.