On: Money creation in the modern economy (2014) [pdf]

[tomhoward]

A financial asset – a stock, a bond, a loan contract, a promissory note, a bank note, a warrant, a future, an IOU...

https://en.wikipedia.org/wiki/Security_(finance)

[bradwood → tomhoward]

I always thought a future (as well as an option) was a contract -- as distinct from a security. In fact, a warrant is a securitised option.

So the nuanced question should be: "What is the difference between a contract and a security?"