bang want sixpence

I am a german student, stuying english at a university.
I came across this saying and have been surfing the web and researching in numerous idiom collections, but i am unable to find out its meaning:
I'll give you the whole sentence:

James McLaren invested 50 grand in venture and bang went sixpence.

I am to find out whether, formally this one sentence could be a very short Short Story and thus i have to find out what the latter part means.

thanks in advance

[Tdol]

Bang went = he lost