I tend to favour a DCA approach. I came across the research on Vanguard myself and, after much hesitation, did a lump sum investment in REITs and other equity ETFs. This was in January 2018, just before the market dropped. In the 2 out of 3 times that you do a lump sum investment and you do produce better results, you'll be happy of course. The question is: Can you stomach the sharp losses incurred after your lump sum investment if the market turns south for you? We are talking 8-10% here, more than what your REIT would pay you in a year or two. If you are not prepared to face this, then psychologically you are better off doing the DCA approach. So personally, I feel it's important to factor in how you would feel based on a negative outcome from doing a lump-sum investment.