Investopedia defines Scalability as: "A characteristic of a system, model or function that describes its capability to cope and perform under an increased or expanding workload. A system that scales well will be able to maintain or even increase its level of performance or efficiency when tested by larger operational demands." This may be a basic question to some, but is there an industry standard for calculating scalability for a trading system? If so, how is it done and does the methodology change across financial instruments (equities, derivatives, bonds, futures, currencies, etc.)? Thanks.