Tisco Securities said there was a sign of "overbought" as the index advanced three straight weeks, gaining 8.1 per cent in this round.
"Profit taking is iminent though foreign fund inflows would continue," it said in a research note.
At 11.26am, the SET index gained 13.43 points or 0.97 per cent to 1,392.96 points, on turnover of Bt21.5 billion.