Chart, page-16643

https://www.investopedia.com/terms/g/gap.asp

Limitations of Gaps
There are limitations despite gaps being easy to spot. The glaring flaw is one's own ability to identify the different types of gap that occur. If a gap is misinterpreted, it could be a disastrous mistake causing one to miss an opportunity to either buy or sell a security, which could weigh heavily on one's profits and losses.


https://allstarcharts.com/gaps-need-filled/

There’s a saying among market participants that “all gaps need to be filled” or “all gaps are eventually filled”, but as with most market generalizations, this saying shouldn’t be taken at face value.

I just grabbed these 2 examples of gapping "theory" off the web.
It's a common misconception, that "All gaps need to be filled" and no one can make such a statement, without being a liar.

Gapping theory is basically the same as superstition.

As is any charting patterns, based over a large period of time, "cup and handle", "head and shoulders" etc.
They don't take any of what is actually happening to the market, or company, into consideration.
And have all the value, of reading tea leaves.

Relative strength indexes, moving averages, and tools that measure sentiment, such as candles etc, can have value, in my opinion.

But these are all just short term trading tools and of no value, whatsoever, to an investor.

My opinions only, on the subject.
GLTA!