Natural filtration
= Natural filtration
{title2=$\mathcal F_t^X$}
{wiki=Filtration_(probability_theory)}
The natural filtration of a stochastic process $X$ records its history:
$$
\mathcal F_t^X=\sigma(X_s:0\leq s\leq t),
$$
possibly completed and made right-continuous when the usual conditions are required.