According to the reference, Securities is a Dictionary<Symbol, Security> so you can access your Security objects with their ticker Securities["IBM"].Price

However, in the sample RiskManagementModels, this is used:

for kvp in algorithm.Securities:
    symbol = kvp.Key
    security = kvp.Value

How does the above construction work? I am a relative beginner, but from what I know about dictionaries, kvp would be the key and Securities[kvp] would be the individual security.