
The SET index was the highest since January 1997.
At times of financial crisis, the index nosedived to 355.81 points at the end of 1998, from 1323.43 at the beginning of 1996.
Foreign capital inflows have pushed Thai baht to the 10-year high at above Bt34.50.
Bank of Thailand Deputy Governor Atchana Waiquamdee said that the authorities didn't mind the currency's rise because it was moving with regional units.
"Since the US dollar has a generally weak tone and all regional units are strengthening, there is no need for the central bank to intervene (to curb the baht's rise)," she said.