It's likely to do with the fact that I've only been posting...

It's likely to do with the fact that I've only been posting since September and that I'm only interested in the recent share price decline which has occurred since that time.

Concerning Brainchip's Beta, this report gives Brainchip a current Beta of 1.18 vs. the ASX 200. Meaning that the stock is very strongly influenced by day-to-day market news, or by the general health of the economy. Note that the report highlights that "on days when the market is up, BRN shares tends to outperform the S&P/ASX 200 index. However, on days when the market is down, the shares generally decrease by more than the index."