In 2007, the Swedish Financial Supervisory Authority received 170 reports of suspected insider trading from businesses dealing in the buying and selling of shares.
The equivalent total for 2006 amounted to 79 reports of suspicious dealings.
Since 2005, businesses have been obliged to report any suspected cases of insider trading and market abuse. This is thought to be the main reason for an explosion of new cases over the last two years.
"The markets have learned much better. They really blossomed during the second half of 2007," said authority spokesman Erik Saers.