For example, UBS asked brokers to tailor their "run-throughs" - their overview of market sentiment and activity that they discuss with traders at the other banks - to benefit UBS's position in yen interest rates.

BBC: UBS sign

For a discussion of what causes an activity to rise to the level of a trade or business, see Part 1 of this overview.

FORBES: Overview Of The New 3.8% Investment Income Tax, Part 2: Passive Activities