As opposed to variable interest rate funds, fixed-rate funds never aspire to provide attractive profits. Its advantage is that, compared to beating that variable rates have taken the past few months, the most conservative funds have remained stable.

On the whole, a fixed-rate investment is that which guarantees an agreed amount of interest over a predetermined period in addition to the capital invested. The state and the autonomous communities in Spain issue fixed-rate bonds with which they obtain sources of finance. Certain companies do the same, finding the money they need in this type of market.

A fixed-rate portfolio has three main characteristics: pre-agreed performance, liquidity in a predetermined period of time and capital protection. However, the security of this type of investment has three possible variations:

1.- Intermediary risk: this is avoided by evading so-called financial fly-by-nights and instead seeking the advice of entities registered by the Spanish stock market watchdog, the CNMV.
2.-  Issuer risk: sometimes investors acquire promissory notes issued by companies that are not able to pay, companies that haven't been able to raise funds via the banking system, and that offer interest rates way above the market rate.
3.- Market risk: a rise in interest rates causes the drop of the values issued to a lower rate.

In theory, fixed-rate funds can be divided into two main groups: those with a fixed performance or with regular payment of interests, and those that are issued with an implicit performance or single payment of interests (zero warrant) at maturity. The former are those that give regular payments to the investor in the form of interest (warrant), normally with an annual or half-yearly period of maturity. The latter are fixed-interest funds that give an implicit performance or zero warrant, whereby the investor's compensation is calculated by the difference between the price at acquisition and that at maturity, without regular interest payments. In other words, buy at 980 euros something that will give you 1,000 euros within a predetermined time limit, giving me a profit of 20 euros. 

Profile of the investor
The most common characteristics of a fixed-rate investor are that of a conservative investor, who looks for alternatives to make a modest profit from his savings without risk. These are people that do not need a regular profit and prefer to receive a predetermined capital in the future, as at the time of maturity they'll receive both the interests and the amount invested. The fiscal incentives are the great advantage, as not having regular interest payments means not having to declare the funds.

Apart from this type of investor, professional brokers include this type of investment in the portfolios of their clients to compensate the risks of other types of funds.