Futures have a time limit. There is a contract every month every year, so if you buy a contract for several months, you have to sell it or move it before the contract expires (that is, replace it with an unexpired futures contract). Earned money can be exchanged for a lifetime, but individuals cannot deliver futures in kind. Only production enterprises can deliver futures contracts in kind, and physical futures are generally consumed in warehouses that year, not for ten years. Put it for ten years, even the best corn and soybeans. The wheat is moldy and rotten.