Buying with the intention of holding for years and not reacting to ordinary price swings. Its advantage is mostly arithmetic rather than insight: every round trip on the PSE costs a bit over 1% in commission, VAT, exchange fees and the 0.6% transaction tax, so the same money traded twelve times a year pays that toll twelve times. Holding also defers the tax on the gain. The cost is that you sit through the falls as well as the rises.
See every term in the full PSE investing glossary.