The Swiss franc, along with its related exchange traded fund, has been gaining strength in the past few months as Eurozone concerns re-emerge, but banks are making aggressive changes to help weaken the currency.

CurrencyShares Swiss Franc Trust (NYSEArca: FXF) is up about 3% the past month to its highest level since May.

Recently, UBS AG (NYSE: UBS), Switzerland’s largest bank, stated that it will begin charging financial institutional clients for cash balances in Swiss francs on Dec. 21, citing “continued prevailing market situation affecting the Swiss franc,” Bloomberg reports.

“We encourage our customers to keep their Swiss franc balances as low as possible,” UBS said in the article.

Since Aug. 2011, UBS has placed a “temporary excess balance fee”  in cash clearing accounts that had net inflows above a certain point.

Last week, Credit Suisse Group AG, the second-largest Swiss bank, said it would start putting negative rates of as much as minus 1% on cash clearing accounts in francs.

Showing Page 1 of 2