Dollar bulls may be disappointed if they're pinning their hopes on Republican proposals that could clear the way for U.S. companies to repatriate profits stashed overseas, according to JPMorgan Chase & Co.

Of the $2.2 trillion the bank estimates is available for repatriation, the actual flow back into dollars may be around $456 billion, given that much of the money is either already in the U.S. currency or is otherwise hedged or held in illiquid assets, according to analysts Daniel Hui and Niall O'Connor.

The numbers argue that even if President Donald Trump unites Republican leaders around a tax-overhaul plan that includes a one-time levy on offshore profits, the downtrodden dollar may only get a limited boost. After falling to the lowest since January 2015 last month, the Bloomberg dollar index has risen almost 3%, in part as traders factored in the prospect of economic stimulus from tax reform.