And, in a second round, what is the origin of the "long" and "short" in characterizing the respective positions in assets? Any pointers to etymology, first occurrences, or related literature would be greatly appreciated.
Haven't read this so can't vouch for whether they get into etymology.
This chapter discusses the history of option contracts from ancient times until the appearance of Theorie der Prämiengeschäfte by Vincenz Bronzin in 1908. The history examines the use of contracts with option features prior to the introduction of trade in free standing option contracts on the Antwerp bourse during the 16th century. Descriptions of the Amsterdam share option market by de la Vega in the 17th century and de Pinto in the 18th century are reviewed. The specific language of a late 17th century English option contract is provided in detail. The development and practice of option trading in the 18th and 19th centuries, as reflected in merchant manuals of that period, is examined. The article concludes with an overview of late 19th century option trading in securities and commodities.