[highfrequency]

Apple the company issues stock. They are the seller, and some investor is the buyer. Apple uses the money to invest in operations, and the stock goes up over time. Who lost?

Forget about stocks - this is the whole point of trade in general. People have different resources and different needs, time horizons, risk tolerance etc., so the default assumption should be that voluntary trade is positive sum - just like Ford selling a car is positive sum even though there is a buyer and a seller.

[wat10000]

Apple issues stock at $200/share. Bob buys one share. Apple is now $200 richer, Bob is $200 poorer.

Later, Apple goes up to $300/share. Bob sells his stock to Charlie. Bob is now $100 richer, Charlie is $300 poorer. Total change: zero.

Apple is more valuable and that (probably) means wealth was created, but that increase in wealth comes from Apple doing things, not from the trading.

Non-stock trading creates wealth because different people value things differently. A sandwich is worth less to Subway than it is to me, so total wealth increases when I pay them for a sandwich. But stocks don't really work that way. Unless you're buying a stock to exert control over the company, the only thing you're doing with it is using it to make money money. If you're making money by selling at a higher price later, then that comes from someone else paying that higher price, and it's all zero-sum.

I was responding to "Pension funds, banks, HFT firms can all make money while trading with each other." I readily accept that economic activity is not zero-sum, creates wealth, and that trading stocks can help enable that. But just trading by itself doesn't make money.

[lotsofpulp]

"Making money" at the same exact time does not have to be the goal. Bob might want more liquidity and lower volatility now, so he wants US dollars (USD) from Charlie. Charlie might want less liquidity now, but wants to bet on $300 worth of AAPL will have more purchasing power at some point in the future than $300 of USD.