Here's the real reason why demand for Thomson Three units surged

Over 170 units were bought.

CIMB analysts noticed smaller crowds and lower take-up rates for new project launches. Higher demand for Thomson Three came at the expense of lower pricing.

Around 200 units of Thomson Three were launched on 20th Sep and 170+ units were bought (85% take-up rate).

Here's more from CIMB:

The Tembusu andThe Glades were launched before Thomson Three, but have take-up rates of ~60% and ~30% respectively.

We believe the main reason behind the difference in demand is Thomson Three’s lower pricing of S$1,300+psf, compared to S$1,400-S$1,500psf for The Glades and The Tembusu. Based on our checks with agents, bankers and developers, the TDSR’s impact can be felt as an estimated 20-30% of prospective buyers fail to clear the TDSR limit (60%).

These are largely investors already holding two or more properties. Also, loan processing now takes longer.