MIT computer scientists can predict the price of Bitcoin

For example, futures and options are zero-sum because every dollar of profit that one trader makes is offset by a dollar of loss from another trader.

But stock markets are not zero-sum. Prices can be bid up without a single share changing hands, creating new wealth out of thin air, and everyone wins. Conversely, prices can go to zero, destroying wealth and making everyone a loser.

Same thing for most other markets you can think of, from real estate to used cars to your local flea market. As with bitcoin exchanges, none of these are zero-sum since there doesn't have to be a loser for every winner.

A more compelling argument against zero-sum is that traders and investors have different time frames and objectives. And, indeed, the classic argument in the futures market is that a farmer who buys a hedge from a speculator represents a potential positive outcome for both.

Marketplaces are not at all inherently zero sum games. Wikipedia's definition (which is a fine one) is: "a participant's gain (or loss) of utility is exactly balanced by the losses (or gains) of the utility of the other participant(s). If the total gains of the participants are added up and the total losses are subtracted, they will sum to zero."

The key thing here that is is measured in utility (not in the price of the good). Of course every trade or transaction is flat in that I sold it to you for the price you bought it at (that is obvious and non-what a zero sum game means). The issue is whether we are both made better off or not.

If I don't want to bear the risk of holding bitcoins and am happier mitigating that risk by selling them for dollars, my utility increased. Similarly, if you purchased them from me because you want to bear such risk, your utility increased. Even removing the risk/uncertainty from the equation, my willingness to pay for a good is not the same as the market price. Thus, if I sell bitcoins bc my value of them is less than the current market price, then I am improved. Similarly, if you value bitcoins above the current market price and buy them from me, then your willingness to pay was higher than the price you paid. Thus, you have significant consumer surplus from that trade.

There are called pareto efficient transactions. Most transactions are actually pareto efficient where at least one of the individuals increased their utility and no one involved in the trade decreased their utility.

This excerpt does a good job articulating this: "Specifically, all trade is by definition positive sum, because when two parties agree to an exchange each party must consider the goods it is receiving to be more valuable than the goods it is delivering. In fact, all economic exchanges must benefit both parties to the point that each party can overcome its transaction costs, or the transaction would simply not take place."

vs

>I'm not arguing that it is zero-sum

So, what are you saying there then.