I think weird TA like this is just a way for organized players to justify something to the regulators. I think the thought process is like this…“Oh… we bought calls and let’s take NIFTY 500 points up… But, first let’s draw a cup and saucer in case SEBI wants a clarification on why we bought today of all days…” “We bought puts, but there’s no bad news… and we can’t create bad news either…let’s just draw a head and shoulders before we drop it…”.
Gaps usually work intraday because unorganized retail is given the illusion of “oh… it went way up have to buy…”, i.e., greed, then organized players come into sell creating a “gap fill”. It works because retail unorganized players think “predictably”(Fear or greed) and it gives the good oppurtunity to make money by organized players. It’s the same technique you use, which creates the gap fill phenomenon. But there’s no point betting on it after day is over and especially not after a week or so.
Having said that, another main reason it works is, as more players(who believe in TA) and algos get involved, it becomes a “self fulfilling prophecy”… I think that’s why things like trend lines/support/resistances seem to work. Some traders look for “price action”…what they actually mean is “Let’s wait for some big player to make the action first… then I’ll jump in”. Essentially it’s “frontrunning” with a delay for confirmation. Nothing new under the sun.