The CME Group's first Bitcoin futures contract expires Friday 2018/01/26 at 4 pm London time. What effect (if any) will this have on the Bitcoin price?
Open interest on the January contract dropped from 560 on Friday 1/19 to 287 on Wed 01/24[1], whereas Feb numbers jumped from 613 to 768 during the same time period.
This shows that those purchasing futures are doing so more as a way to indirectly bet for or against Bitcoin than to actually profit from the completion of a contract, and are possibly nervous about market manipulation around the closing date similar to what happened with the price drop and rebound before the Cboe's contract close on Wed Jan 17.
As to the impact on the actual price, you must look at the numbers involved to see how each side might profit from a price move. At the contract's 5-to-1 ratio, 287 open interest represents 1,435 bitcoins.
Thus, for every $1000 USD increase/decrease in price, that represents $1.4 million change for those with open interest.
On GDAX alone at the current price of $11k, buyers would need to purchase $15.4 million to make the price move up $1000 (above $12k), and sellers would need to sell 1,915 btc ($20.1 million) to make the price move down $1000 (below $10k). If the market jumps in and backs such a move (not guaranteed since GDAX only represents only about 15% of the market share), this represents a return of 9% for buyers and 5% for sellers, and is only realized if they are able to exit their buy/sell positions at profitable prices, which adds additional risk.
However, they are also moving the prices of the other futures, which had an open interest of 1459 on Wed, which increases the potential change by just over 5 times, giving a potential 45% return for buyers and 25% return for sellers, though this requires keeping the price up long enough to close their other positions before the price bounces back.
These represent relatively minor incentive to move the market than what was anticipated from futures back in December.
Conclusion
As it stands, futures buyers have more to gain than shorters from moving the market, and so we can directly expect a small net positive effect on the price from the futures investors near close, with the potential to be amplified by other independent investors anticipating and helping the move.