Over 1–3 years, stock prices are noisy — driven by sentiment, macro data, foreign flows, budget rumours. Over 10+ years, prices tend to track the underlying business's earnings growth.
This is why long-term investors ignore quarterly noise: the signal-to-noise ratio in a single quarter is terrible.
Practical implication: check your portfolio quarterly at most. Daily checking makes you sell winners and buy losers, in that order.
The two questions to re-ask each year: (1) do I still believe this business will earn more in 5 years than today? (2) has my personal situation changed enough to re-do my asset allocation?