Which is probably true.

I've heard from friends of some of the typical shenanigans played among state actors involving oil and gas, and that would be the least underhanded thing going on.

I am saying that the timeframe between a breakthrough in fusion, and it having a measurable effect on energy usage is so large that "money" will not reflect it with immediate and large moves in the market.

‘Breakthroughs’ like fusion typically does are useless. Something viable is not.

When something viable happens, you’ll see markets move, because market pricing is based on expectations of future performance, not current performance.

My non-expert understanding is that Futures are a specific financial instrument with set expiry dates, and are about locking in prices for these commodities at a certain date. The vast majority of these would be expiring in under low digit years. I am arguing that the ramp up time for fusion to go from "feasible design" to "having a significant impact on the the amount of oil/gas consumed" is much longer than most futures expiry dates, and would therefore have little impact.

That said, I guess people can (and do) buy futures with expiry dates for more than 10 years out, presumably they just have to find a counter party. Is this a significant amount invested? Bringing me back around to my original (and honestly asked) question: How many years out do oil/gas futures project?

For me, I'd take 'viable' to mean something like a demonstration plant actually working somewhere, a team with the ability (somewhat proven) to reproduce it at scale, and after that exists the math pencils out it's profitable even on a risk adjusted basis.

At which point, it's a real thing that will happen, and prices will start to adjust based on the likely adoption curve (with various speculative values of the curve of course too).

Which yes, may or may not change future values for delivery depending on the timeline.