P.S: interestingly if you look at my example, a 20% gapped down in ABC actually hurt you a lot less than a 20% gapped down in XYZ even thou you bought 6666 shares of ABC comparing to only 2000 shares of XYZ. In fact, a 4,000 dollar loss comparing to a 12,000 dollar loss. An 8% loss comparing to a 24% loss. Just to show how important it is to understand risk management.

If the stock price is $3.00, you would buy 300 shares (total $900). (Usually the stop loss is much smaller on cheaper stock and you can buy more shares)
The idea is not to risk more per trade than you allow for your account and to calculate it using the stop loss point BEFORE the transaction.
If you use the same amount on all trades, I think it is wise to have different purchase amounts for penny stocks and more expensive ones.

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Saw some weakness in the price bids near noon, so sold the remainder at 9.82, so the whole amount gain was about $1.10 per share. I would like to buy back in ONNN for a longer term once this quarter shakes out, if the price is attractive.

That was essentially my point. It is percentage returns that matter, and at higher prices, it is harder to identify where a stock is "overvalued", while bottoms are relatively easier to identify, because the point values are larger, making stop placement more difficult.

There are a few charting methods that do not take this volatility relationship into account, however.

Positive divergences lend themselves to stops based on breaks of support. Bottoms are more easily identified that tops, so the signal that a trend is resuming to the downside is fairly clear. I've noticed that these breaks of support are often accompanied by spikes in volume.

For negative divergences, stops based on price are likely to get you whipsawed if they are set fairly close. I've seen numerous instances of a divergence signal being given, having the stock spike up to a slightly higher high, and then fall sharply in a short amount of time.