Broadly speaking, there are two types of investing: systematic and non-systematic. The first is a methodical approach and does not rely on one’s emotions or gut feelings.
You put a fixed amount into the fund every month, regardless of market behaviour and the price of units.
If the price of the fund goes down, you buy more units; if it goes up, you buy fewer units.
This approach is called ‘dollar cost averaging’. Simply it means that your average unit cost will be less than if you made an equivalent lump sum investment at its unit cost. Put another way, as prices fluctuate, you get more units.
The statistical effect becomes more obvious over time, especially in volatile markets, as the illustration below shows.