Continuity in Probability 
Could someone give me a simple explanation of property 4?
Context: Currently learning a bit of financial mathematics on my own to see if it is a field I really want to get into. The first 3 properties make it a stochastic process but the 4th condition I am unfamiliar with. The fourth property to me seems to limit how big the growth from one point to another is, but I am unsure if the interpretation is correct or not.

I interpret it the way that Henry does in the comments on Graham Kemp's answer: Heuristically, any change in infinitesimal time is almost surely infinitesimal (i.e., is infinitesimal with probability one).
