Meme stocks GameStop and AMC tumble Tuesday on heavy trading volume

Meme stocks swung violently on Tuesday with huge trading activity in the shares.

GameStop dropped more than 5% with over 10 million shares traded through midday, already doubling its 30-day average full-day volume of 4.6 million.

AMC Entertainment shares lost nearly 4% before turning green around noon ET with 132 million shares traded, also doubling its 30-day average of 51 million.

The reason for the moves were not immediately clear, but both stocks are up big this month amid a broader comeback rally on Wall Street so some investors could be using that pop to take profits in the volatile shares.

There were some large block trades of GameStop in early trading on the NYSE. Outside of the open there were two trades of more than 20,000 shares apiece, according to FactSet data.

The NYSE briefly halted both stocks for volatility shortly after the open as the stocks popped then dropped.

The duo just notched a strong week as loyal retail investors kept pushing up the shares. GameStop shares rallied a whopping 67% last week as traders got a vote of confidence when chairman Ryan Cohen bought additional 100,000 shares of the video game retailer.

Meanwhile, AMC saw a 28% gain last week after the movie theater chain revealed its plan to buy a tiny gold miner. However, the move to take a significant stake in the gold miner with a shaky financial history confused many Wall Street strategists.

This is a developing story. Check back for updates.