When Not To Buy

On valuation I’ve seen in my 2 years journey that you make money when the valuation is so cheap that you don’t need to do too much hardwork on valuation. And probability of not making money increases when doing valuation becomes very difficult.
Scenario 1: I bought a NBFC company named CSL Finance Ltd in February 2021 with price being lower than the book value after substracting all the gnpas( which was very low). The promoter was buying from open market. The mgmt managed the NPA to be stable throughout the covid. The adjusted PB ratio was 0.65. It was a no brainer buy at that price and it became a 3 bagger. Didn’t fall at recent sell off at all. Still the company is available at 1.2 PB ratio but now the valuation is little bit hazy. I mean it’s no longer a no brainer buy.
Scenario 2: I bought Prince pipe after it became a multibagger. The PE ratio was 36 but the earning growth was also superb. It was a 25% grower company at 36 PE so I thought even if it grows by 20% I’ll make money because the ROE ROCE was good. After I bought next 2 qtrs results were also good. But then the crude price shot up margins reduced and the stock price is still consolidating and now in the lower range. Though the sector has tail winds. But I’ve lost in terms of opportunity cost. I could have invested now. Because the valuation is much better now. 15% grower at 22 PE with structural tail winds. But will I buy it? No there are much better opportunities which represent no brainer buys.
Scenario 3: Krsnaa diagonistics, a moated player+good management+ Huge runaway for growth. Excellent growth in last 3-4 years. The stock corrected by 50% because everyone thinks increasing competition in Diagonistics sector js going to hurt the existing players. it’s true for dr lal path labs and other like them. but krsnaa completely operates in different field. So here we have a company which can easily double the earnings in next 2-3 years due to huge operating leverage. So it’s a no brainer buy at this valuation.