Note that one can never increase his bitcoin investment portfolio through trading but rather you will decrease or loss your bitcoin through trading, because trading isn't something very easy as people thinks it is.
I believe this is an exaggeration. There are people who increase their Bitcoin portfolio in trading, Not because someone is not able to do a successful trade, everyone is a failure. That is a wrong assumption, IMO.
HODLing is the only way out. You need to have a means of income to enable you buy bitcoin, and if your income is very low, try to get a second means of income, if you really believe in bitcoin. No amount is too small to invest with, the earlier the better as time waits for no one.
If you are talking about the increase in Bitcoin portfolio, hodling alone cannot increase your portfolio, you need to continuously buy Bitcoin and hodl to increase your portfolio.
If you are talking about realizing profit, hodling is not the answer but selling at a higher price. Since to realize our gain, we need to stop hodling and sell our stash at a higher price.