As a decision matrix, even if you are sitting on huge capital gains, yields matter.

If yields are puny, and forward prices are not exciting, the easy decision is to sell.

BUT for an investor thinking whether or not to buy, yields matter even more. Question is then whether there is positive carry, and whether such positive carry is sustainable.

A lot of people I know jumped into the market because of slight positive carry (i.e. rental minus (mortgage+monthly maintenance) equals $500-1000 per month). But they forget to factor in vacancy reserve cost, agent fees, repair costs etc.

So they jump into a new project, and now, upon TOP, they find that half the buyers are investors, and there are 500 people all advertising for rental at the same time. And they are left with an unpalatable decision - either leave the place empty for a while or accept less rental, which takes away their positive carry, sometimes bringing them into negative carry situation.

At a time when interest rates are at an all time low and can only go up, and with an unprecedented 200,000 units coming onstream next couple of years with many investor units in its midst, and with the government restricting foreigners, that's a scary proposition.

Does yield matter ? You decide.