The largest group, currently, of investors in classical stringed instruments are, quite naturally, professional musicians and some musicians have done very well from the resale of purchases made early in their career. Some, on the other hand, have found that fortunes spent many years ago evaporate when resale is attempted for reasons of revised or disputed attribution or condition problems. Many pedigree instruments are traded between musicians and not in the 'open' market.
Some investors are philanthropists and are happy to acquire instruments for talented players, who would not normally be able to afford the considerable sums needed to buy what is required. The arrangements vary but could involve a loan or a leasing arrangement and in some circumstances an outright gift, perhaps with tax relieving implications.
Speculators in instruments for any reason beyond philanthropy or music making for the greater good are seen by many who appreciate music as rather invidious. Speculators, on the other hand, do bring to light valuable instruments that would have been overlooked by the less knowledgable. This is per se unusual in the instrument market now with the wider awareness of instrument and bow values limiting the opportunities for the professional bargain hunter.
The modern dealer may fall, to any greater or lesser extent, into any category described here and may not own an instrument or bow that he offers, he may be selling on consignment for a commission. Some dealers have shops, some restore instruments with occasional or regular purchases or sales of instruments or bows. Some dealers operate their trading as part of a wider musical career involving teaching or playing and may not construe their trading activities as their main occupation.
A rarer type of investor, these days, is the collector, who collects solely on the basis of his appreciation of the quality of workmanship of instruments, or bows, yet does not play them. This investor does not necessarily fall into the category of speculator; he collects for the pleasure of it rather than the profit. He may loan out instruments from time to time or not as the case may be. If the latter, then he may have role in the preservation of masterpieces for future generations to experience, despite any prima facie case of selfishly denying others their use. A collection of this type could fall into the category of a private museum.
During the 19th and most of the 20th century collecting instruments, as a collecting activity, was more prevalent. It was an activity of the "educated" and wealthy. Joseph Gillott, the pen manufacturer in Birmingham (UK) is an example, his collection was by auction at sold at Christies in 1872 and the Gillott name is associated with several of the finest instruments of the most eminent 17th & 18th century Italian instrument makers. Some earlier collectors acquired instruments and bows as a sub-category of a wider collection of decorative and fine art. In a modern sense these were "lifestyle" purchases rather than the pursuit of a particular functional aim. It should be remembered, however, that recreational music making was far more common before the television era began in earnest after 1945.
Auction prices are a matter of public record and some statistics from the auction world follow, which illustrate the favourable growth in recent years (prices include buyer's premium):
Antonio Stradivari, 'cello, dated circa 1691, sold in 1984 at Sotheby's, London for £275,000, sold again at Christie's in 1992 for £605,000
Joseph Guarneri del Gesu, violin, dated circa 1742, sold at Sotheby's in 1972 for £26,000, sold again at Sotheby's for £572,000 in 1988.
Antonio Stradivari, violin, dated 1711, sold at Sotheby's, London for £165,000 in 1987, sold again in 1995 for £386,500
Joseph Rocca, violin, dated 1845, sold at Sotheby's, London in 1977 for £9,350, sold again in 1980 for £17,050, sold again in 1985 for £35,200, sold again in 2000 for £89,500.
It should be noted that the value of an investment can fall as well as rise. A violin by Jacob Stainer, for example, at the end of the 18th century would have achieved roughly half the original purchase price a hundred years later. Instruments by members of the Guarneri family sold at auction seldom re-appear at auction.