Enlargement of Filtrations -- A Primer

Peter Ouwehand

Published 2022-10-13Version 1

In stochastic analysis, the flow of information through time is typically modelled using a filtration. We introduce some of the basic ideas involving enlargements of filtration. Here, we focus mainly on initial enlargements, where a given filtration is enlarged with knowledge of an additional random variable. This has applications to the modelling of insider trading in mathematical finance.