Since 3 September 2003, it has been part of Nasdaq Nordic (previously called OMX).
On April 1, 1990, trading was moved to a new digital system: HETI (Helsinki Stock Exchange Automated Trading and Information System, and in Finnish a rough backronym for "immediately"), which replaced the electro-mechanical trading system originally introduced back in 1935.
HETI enabled remote traders to conduct transactions on equal terms with those in the trading room.
It is a market value weighted index that consists of the 25 most-traded on Nasdaq Helsinki.
[3] Normal trading sessions are from 10:00am to 6:30pm on all days of the week except Saturdays, Sundays and holidays declared by the Exchange in advance.