The decreasing of the price-spread shows that the hecticity of the market is decreasing, the market is approaching the equilibrium.

What sayest thou, Bully Bottom?

The cross product can be derived like so: given a pair of vectors 𝜉 and 𝜂, solve for a vector 𝜁 which is perpendicular to both 𝜉 and 𝜂, i.e., whose dot product with both 𝜉 and 𝜂 is zero.

I could wish, that these sciolous Zealots had more Iudgment joyn'd with their Zeal