As the morning session ended, the Stock Exchange of Thailand index shed 28.08 points or 1.99 per cent, to 1,380.66 points. Only 207 stocks managed to advance while 825 stocks were down.
Prior to the open, the Securities and Exchange Commission as well as business associations involved with the stock market issued a statement saying the blast at the Ratchaprasong intersection on Monday night would cause psychological impacts on the country's investment and economic climate.
"Nevertheless, there is no significant change to the economic stability and the fundamentals of listed companies. Moreover, the government has launched short- and long-term stimulus measures which are being materialised. This will move the economy forward. Investors should closely follow information from reliable sources and make a thorough decision," they said.
They also expressed deep condolences to the victims.
The joint statement was issued by the SEC, the Stock Exchange of Thailand, the Federation of Capital Market Organisations, the Association of Securities Companies, the Association of Asset Investment Companies, and the Thai Listed Companies Association.
The Thai baht has also weakened in the aftermath of the deadly blast.
At the open, the Thai baht was at Bt35.58 per US dollar, down by 0.23 per cent from Monday closing of Bt35.50.
At 1.46pm, the Thai baht was traded at Bt35.56.