Is rapidly increasing volatility among memory stocks a sign of a potential bubble popping?

By any historical metric, rapidly increasing volatility in a sector has never been a good sign. It has most often pointed to signs of a bubble on the verge of bursting, whipsawing back and forth with crazy up and down swings, eventually culminating in a drop far off its highs that it ultimately never recovers from.

Now we're seeing it again today, in particular among memory stocks. SNDK is not a penny stock, it is a large cap stock worth over $200B. Yet since May, it has experienced almost a dozen +10% or -10% single day closes.

If not the sign of a bubble popping or a cyclical top, what is going on here?