My first reason is simple; to invest I need funds, I owned almost 10 companies, so the little money I could put in once in a while would not grow them enough and would be costly in fees. It's basically diminished returns at this point, I can't add an equal sum to all my investments at once, so it would take months to increase all my investments once.
Second, to me there are enough factors to make the chances of an upward trend less likely. I prefer to have cash to invest on opportunities, when stocks I like dip below what I consider fair value, as I have done with the companies I sold today. My buy signal is just Exponential Moving Average set to 100 days, and then analysis.
And Canada is likely to crash soon

I'll be moving cash to USD.