A key trend in the gold market has just been broken, and bitcoin could be to blame.

The gold miners ETF (GDX) had fallen nearly 15 percent from its September highs while gold has plunged to lows unseen since the end of July. This is curious, says Larry McDonald, head of U.S. macro strategy at ACG Analytics, as the move lower in gold has also been followed by a move down in bond yields, which according to the strategist is very rare.

"Over the last two years, every time rates have come down, and this week rates have moved lower, you had gold go up," he said Friday in a "Trading Nation" segment on CNBC's "Power Lunch." "Almost every time, there has been an 82 percent correlation between gold and bonds. This week, for the first time, that correlation broke down, and I do think it has something to do with bitcoin."

According to McDonald, there could be even more downside for gold, given the rapid growth of cryptocurrencies, bitcoin and otherwise.

"If you add up all the cryptocurrencies and the liquid gold that's in the market right now, the cryptocurrencies in market cap are now 23 percent of the liquid tradeable gold," he said. "That's up from 2 or 3 percent a year ago, so cryptocurrencies are definitely eating into the gold play."

In fact, while gold has fallen more than 2 percent in the past month, bitcoin has actually more than doubled its value in that time, according to Coinbase.

Following the launch of bitcoin futures contracts on the CBOE, bitcoin soared and was around $16,800 Monday morning. Gold, on the other hand, was still sitting near its July lows.

Phillip Streible, senior market strategist at RJO Futures, says that the performance of bitcoin futures contracts, the first of which began trading on the Cboe on Sunday, will be a key determinant of gold's next move.

"If all of a sudden we see bitcoin futures go into a free fall and collapse, [gold will benefit]," he said last week on "Power Lunch." "Safe haven, store of value, it will start to get people back."

The next exchange to launch bitcoin futures contracts will be the CME on Dec. 18.