Ask HN: What are the classic signs (if there are any) of market manipulation?

I've been following the market recently due to its unprecedented recovery. I am also dabbling in some home-grown strategies for how to position myself as well.

One thing I've done is I've positioned myself short with some oil and gas ETFs. The peculiar thing I noticed a few weeks ago was that early in the morning the options prices on these equities would spike extremely high, then throughout the day would taper off back to even (no gain / no loss).

For a while I was thinking this was some hedge fund or other powerful / wealthy entity just buying up every last options contract they can. I fail to see how it's not the right strategy right now, as all of a sudden the entire world (to a very large degree) just stopped driving places.

But then it became clear to me that currently there is no reason to really be short the market in any significant capacity because the major indexes just keep hitting all-time highs just about every day.

Then I started considering whether those 2 things are somehow related. People keep talking about extremely solid fundamentals, yet we are in the middle of one of the worst crises human civilization has ever experienced).

I have no knowledge of how these automated trading systems run by large banks or hedge funds work, but if this is happening on a grand scale (short-sale options are dropping significantly in price throughout the course of each day), and it's an important marker of market health to these trading systems, I can see how these algorithms could see this as an extremely positive sign thus all of the equities I've been following appear to be very seldomly trading lower than 2 standard deviations above their 20-day moving averages (Bollinger Band indicator).

If one wanted to explore this further, dig a little deeper to find signs of market manipulation, where would one typically go and what signs would indicate such activity?