Who is Laurence 'Larry' Parmenter from Libra and what is their importance?

Larry Parmenter is an opportunist who used the turmoil in Cuba to make a few personal investments. Expecting Cuba to go the same way Guatemala went, Parmenter arranges for several buddies to become involved in American businesses in Cuba. Parmenter expects to make a great deal of money when Castro is overthrown and America invades the country. Instead, Kennedy calls off the air support, causing the invasion at the Bay of Pigs to fail miserably.