YTD total return is calculated as price return + dividend return. This is calculated as follows:
(Ending Price + Dividend Income - Beginning Price)/Beginning Price.
Yield as seen on Yahoo Finance is an annualized measure. The way that it is calculated takes the dividends paid thus far this year and then assumes that the last dividend paid will be paid for the remaining months of the year. Looking at the dividend history for PSA, it has paid 5 monthly dividends thus far for total income of $1.006. This is the portion that would be added as the 'dividend income' part of the formula above which is different than the yield measure. This is why the yield looks larger than YTD total return.
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