Dozens of staff at Facebook's Dublin office are set to cash in shares in the company worth thousands of euro as rules preventing them from selling their holding in the firm end.
Like a lot of listed companies, Facebook attracted staff through a mixture of salary and a share option known as restricted stock units (RSUs).
These RSUs are locked up for between three and four years, preventing employees from cashing in on them immediately.
For most of Facebook's early staffers in Dublin that lock-up period came to an end on Monday.
That means they can now sell their stock on the open market.
The sales have been delayed, however, because US markets are closed until at least today because of Hurricane Sandy.
The end of the lock-up period comes at a relatively good time for employees.
Around a third of the Dublin staff were sitting on stakes worth more than €100,000 (£80,000) when Facebook, founded by Mark Zuckerberg (below) went public in May, but the drop in the firm's share price since then cut their stake by almost 50%.
Shares, however, have rebounded in recent days, surging 12% last week after the social network reported better than expected third quarter results.
The stock is now trading at $21.94 (€16.90), down on the $38 (£30) it began trading. The windfall that shares will bring to Irish staff has been trailed for some time, and the Dublin stockbroking community has been alive to the opportunities it may bring them.
It was revealed last February that at least one firm had cold-called staff offering their services, while another is believed to have sought a formal tie-in with Facebook's office here.
Many of the staff have already allocated their payouts for big ticket items, such as house deposits and the like.
Overall, about 283m shares owned by staff will be eligible for sale once markets reopen.
Apart from the staff shares, a number of other investors will be eligible to sell shares that had been locked up since the IPO.
Under stock market rules, investors who held shares before the flotation could sell them at the IPO, but then were prevented from selling more of these 'private' shares until a certain point in time.
The lock-up periods for these shares began to expire earlier this autumn, and now more are becoming eligible for sale.
High-profile venture capitalist Jim Breyer is just one investor who is selling some of his shares.
Stock market filings show he will sell 3.5m shares.