Stability of market price is frequently a consideration of great importance. This quality should never be confused with the quality of safety. Safety means the assurance that the maker of the obligation will pay principal and interest when due; stability of market price means that the investment shall not shrink in quoted value. These are very different things, tho frequently identified in people's minds. An investment may possess assured safety of principal and interest and yet suffer a violent decline in quoted price, owing to a change in general business and financial conditions. In times of continued business prosperity very high rates are demanded for the use of money, because the liquid capital of the country, to a large extent, has been converted into fixt forms, in the development of new mines, the building of new factories and railroads, and in the improvement and extension of existing properties. These high rates have the effect of reducing the price level of investment securities because people having such securities are apt to sell them in order to lend the money so released, thus maintaining the parity between the yields upon free and invested capital. As an illustration of this tendency, within the last few years New York City 3-1/2-per-cent bonds have declined from 110 to 90, without the slightest suspicion of their safety. Their inherent qualities have changed in no respect except that their prospect of appreciation in quoted price has become decidedly brighter. Their fall in price has been due to two factors, one general and the other special--first, the absorption of liquid capital and consequent rise in interest rates, occasioned by the unprecedented business activity of the country, and, second, to the unfavorable technical position of the bonds, due to an increased supply in the face of a decreased demand. It will be seen that the question of maintaining the integrity of the money invested is a matter of great importance and deserves to rank as a fifth factor in determining the selection of investments, altho it is not an inherent quality of each investment, but is dependent for its effect upon general conditions. If it is essential to the investor that his security should not shrink in quoted price, his best investment is a real-estate mortgage, which is not quoted and consequently does not fluctate. For the investment of a business surplus, however, where a high degree of convertibility is required, real-estate mortgages will not answer, and the best way to guard against shrinkage is to purchase a short-term security, whose approach to maturity will maintain the price close to par.