If one of these conversions is widening, the reverse conversion might be narrowing.

如果其中一个转换是扩展转换，反向转换便是缩小转换。

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The rules allow taxpayers to reverse their conversions until Oct. 15, either with an extension or an amended return.

WSJ: Tax Report: The Case for Filing Late

Mr. Slott says he plans to monitor his Roths and then reverse the conversions (called "recharacterization") of accounts that have dropped in value or lagged behind.

WSJ: Tax Report: How the Experts Are Handling Their Own Roth IRA Conversions