A future contract is an "agreement" between two parties that one will buy an asset (be it BTC, gold, or whatever) and other will sell it at the contract established price, no matter what is the price in the future. One of the parties will end up in a loss.

Futures trading contracts like the CBOE one is where a bunch of people buy or sell a contract that have an expiration date.

At the expiration date, the contract is settled, and whoever have the contract in the hand will have to make the settlement (is a bit more complicated than that, but its the basic idea)

When you buy a future contract, you dont buy the asset. Only the agreement that you will buy/sell the asset at the contract price. CBOE futures contract end today, but there is already a new one open.

The price of the future contract is different from the price of the asset (higher or lower) because it is not the asset. It is and price established on by the exchange following specific rules.

Every day, there is an adjustment on the contract price, that puts it closer to the asset price. At the expiration date, the price is the same of the asset, and the contract is settled. A new contract is created, and the cicle restart.

No BTC ever exchanges hands.

The movements on the price is related to the price of the asset, because people trade these contracts based on what price they expect it to be on the future. It is not exactly the same, but they are alike.

Before the expiration date, anyone is free to buy or sell the contract, usually with leverage (less money to buy more contracts, but higher risk) provided by the exchange, wich make it a lot easier to trade on higher volumes. And they can buy a short position, betting on the price falling.

But no trades that happen on the future contract exchange only have effect on the price of THE FUTURE CONTRACT. There is no effect on the price of the asset. NO ASSET CHANGE HANDS.

But here comes the catch...

In a small market with no regulations (in money volume) like cryptos, it is pretty possible for someone with enough cash and intelligence to manipulate the asset market, and have its reflection on the Futures Market.

THERE IS NO DIRECT EFFECT. Only a possibility of market manipulation.