Is there inside trading within the stock exchange, where does the buck stop

The recent developments over the past few days would make one wonder if there was some kind of inside trading going on.
If you consider that the value of many stocks nearly crashed, this created panic on the markets.
The results of this are large amounts of stocks and shares sold at ever falling prices.

When the stock/shares prices are falling, at what point you sell your stocks is the gamble.
If you sell it too quickly the market might recover and even increase the value of your stock.
If you sell too late, all the share holders of the stock loose. That is unless they set up another company and buy the stock at its lower price.
What are the reasons for this recent crash in the stock market?
The worst crash since their records began.
Who stood to gain/ who brought the low priced stocks?
Whilst we talk of interest rate increases, some big city fat cats are making millions.