The index lost 12.20 points to end the day at 1,617.89 points, on turnover of Bt56.76 billion.
Brokerage houses attributed the fall to the absence of no good news. All major listed companies revealed their quarterly earning results today.
The index hit the new 19-year high yesterday, at 1,630.09 points.
Month to date, local investors were net-sellers, with net-sells of Bt9.74 billion. Year to date, their net-sells are worth Bt30.57 billion.