When I was still doing it, I did it once a year in a lump sum. But not based on any strategy. Based on procrastination and laziness. If I had really thought about it, I do think I would still have done the investing in a lump sum but at a time when the market seemed to be down (which might mean in October).
I'm known for my laziness!
When I get paid at the end of the month I just set aside my taxes, pay my bills and transfer the rest to my brokerage account. Online banking and investing is so easy.
What happens if you accumulate your yearly savings and the markets keep going up? Do you roll them into the next year and keep waiting?
The liberating thing about my investment plan is that I don't pretend to know what's going to happen and put the money in a diversified set of index funds rebalancing by contributions to whichever ones are most off my asset allocation. I don't have to worry about what the market is going to do and on balance I figure I am better invested than waiting with a stash of cash.
