What are the difference between CAPM and APT

Question

What are the difference between CAPM and APT?

Answer 1

The main differences among CAPM and APT are that CAPM is based upon equilibrium arguments to find to the concept of the Market Portfolio, while APT is based upon a simple estimated arbitrage argument. Though, APT talks about arbitrage, this should be contrasted with the arbitrage arguments we notice in spot versus forward and into option pricing. These are genuine specific arbitrages (albeit the latter being modelled dependent). While, APT the arbitrage is only estimated.