In general, securities firms and Banks to investors to provide this service will charge a fixed interest rate.

一般来说，证券公司和银行向投资者提供这种服务将收取固定利率。

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Funds that invest in fixed income municipal securities are not guaranteed and are subject to interest rate, inflation, and credit risks.

FORBES: Muni Bond Manager's Journal: Looking For Real Value

Keep in mind that municipal securities are subject to a number of risks including, but not limited to: Interest Rate Risk, the risk that the market value of fixed-income securities may fluctuate when interest rates change, and Prepayment Risk, the risk that the issuers of individual securities may prepay them at a time when interest rates have declined.

FORBES: Put Intermediate Muni Funds In Your Portfolio's Rotation