Matrix
Also called: matrices, matrix multiplication, linear algebra
A matrix is a rectangular array of numbers that represents a linear transformation, and it's how portfolios are actually computed. Portfolio variance is a weight vector times a covariance matrix times the weight vector back — one expression that handles a thousand assets and every pairwise interaction between them. Matrix operations are what make large-scale risk and optimisation tractable at all.
Where this is taught
Definitions are the trailer. These free levels turn Matrix into something you play — one bite-size lesson, with worked examples, a quiz and XP.