WSJ's Article on Bitcoin Future Trading and Possible Future Manipulation

Apparently there is a well-known future manipulation scheme called "banging the close". 

Using CBOE as an example: 

 Let’s say you bought 100 Cboe bitcoin contracts expiring in January. The final value of these contracts is set by a daily auction held at 4 p.m. ET on Gemini, a bitcoin spot exchange. The idea behind Gemini’s auction is to bring together many buyers and sellers to determine a benchmark bitcoin price for that day. But suppose you heavily bought bitcoins in the Jan. 17 Gemini auction, offering to pay an abnormally high price. That could skew the benchmark higher, inflating the value of your 100 bitcoin futures contracts. 

 Such a scheme would be tough to execute if there were large numbers of participants in the auction, because it would take a big purchase to boost the benchmark. Also, other traders could see that you were paying above-market prices in the auction and try to profit by selling to you— which would lower the benchmark to more reasonable levels. But Gemini’s volumes are thin: From January to November, an average of $1.3 million in bitcoin changed hands in the auction each day, a sliver of the billions of dollars’ worth of bitcoin traded daily. That has raised fears that a relatively small amount of trading could move the auction price. 

Quite an interesting read: https://www.wsj.com/articles/bitcoin-futures-manipulation-101-how-banging-the-close-works-1513425600