Silver futures increased by as much as 13% on Monday, reaching a peak not seen since 2013. Analysts said that social media investors – influenced by Reddit forum WallStreetBets – may have played a part in its GameStop-like rally.

The sudden and unexplainable surge in silver futures comes just days after the subreddit forum artificially bloated the prices of several unloved stocks such as GameStop and AMC Entertainment.

The move by the Reddit users and those that they had influenced was a direct attack against hedge funds betting against the stocks. The move was also called by some users as the masses’ revolt against the billionaires controlling the “rigged” markets.

Analysts suspect that the same investors may have been responsible for this week’s silver rally. A post on the subreddit, which has millions of members, did call for everyone to make bets on silver to hurt big banking companies. The hashtag “silversqueeze” continues to be trending on Twitter, hinting at a coordinated move by social media investors.

However, some are not convinced that the rally was entirely fueled by the same people. Some posts on WallStreetBets published late Monday and Tuesday suggested that the move may have been co-opted by hedge funds.

One post said that the “fake” squeeze for silver is futile and likely will not make any participants any money. The Reddit user said that people shouldn’t buy into it as it would put them “on the sidelines from this righteous and glorious war” against the one percent.

 Senator Elizabeth Warren raised some concerns about the recent rally and called on the Securities and Exchange Commission to launch an investigation into the matter. Warren said during an interview that she thinks there may be other players apart from those that inflated GameStop and other volatile stocks last week.

“We actually don’t know who all the players are in all this — whether there’s big money on both sides,” Warren said.

The Commodity Futures Trading Commission said that it is closely monitoring the movement of the silver markets and are actively looking for signs of fraud and manipulation. Retail sites warned users that they may not be able to meet the demand for silver bars and coins if the rally does continue.