Stamp Duty is a tax on dutiable documents when you buy or acquire shares. Your trading activities for equity tokens will be subject to stamp duty.
The duty would be 0.2% of the purchase price or the value of the shares, whichever is higher and is subject to a minimum duty of 1 SGD / 1 EUR / 1 USD.
You can read more in the IRAS site here : https://www.iras.gov.sg/irashome/Other-Taxes/Stamp-Duty-for-Shares/Working-out-your-Stamp-Duty/Buying-or-Acquiring-Shares/