Taiwan’s central bank has given overseas investors one week to use funds in the local currency allocated for stocks to purchase shares, in a bid to drive foreign exchange speculators out of the island, according to Bloomberg.

“They aren’t welcome, if they don’t buy stocks within a week,” Spencer Lin, head of the Central Bank of the Republic of China (Taiwan)’s foreign-exchange department, told the news agency. He declined to identify the investors.

The comments came as the Taiwanese dollar advanced to the highest in more than a year this week, pushing to near NT32.0, the highest for 16 months, after improving ties with China prompted the fastest inflows in three years. The central bank said it passed the names of foreign investors with “excessive” holdings of the local currency to the regulator to investigate.

President Ma Ying-jeou’s government permits mainland investors to buy the island’s stocks and acquire stakes in companies.

Foreign-exchange reserves rose by $56 billion in the past year to $348.2 billion, according to a central bank report today, raising speculation the central bank may have intervened by buying the greenback.