Swiss voters will decide Nov. 30 on an initiative that would force the country’s central bank to more than double its gold holdings. The “Save Our Swiss Gold” initiative would require the Swiss National Bank to hold a fifth of its assets in gold within five years. It would also prohibit the bank from selling any of its gold in the future and require that Swiss gold held overseas be repatriated. Organizers of the vote, members of the conservative Swiss People’s Party, say the new rules are needed because a three-year effort to cap the strength of the Swiss franc has left the SNB holding piles of euros, a currency that has been devalued in the wake of the financial crisis. The initiative has drawn opposition from the government, lawmakers and business groups.