How many investors shorted technology stocks in the late 1990s ahead of the bust in March 2000? Alternatively, how many speculators bet against bank stocks in 2007 ahead of the historical crash in financial services companies? And how many investors wagered residential real estate prices would collapse ahead of the peak in the summer of 2006?

Betting against conventional wisdom is a risky proposition. After all, investors generally feel more comfortable in a crowd buying the same assets that are appreciating; we’re conditioned to buy en masse and naturally feel comforted by a rising trend that enriches our bank account. Then the Piper comes calling like he always does when a speculative “bubble” finally draws to an ugly end.

As we shortly conclude the half-way mark in 2009 I’m asking myself where can an investor make money betting against conventional wisdom? In other words, which sectors are seemingly in a speculative “bubble” and absolutely accepted by the masses?

Since the market low on March 9 it’s almost like investors have completely forgotten about the financial crisis. Did it ever exist? Judging by market benchmark performance, mutual fund inflows and investor consensus, the good ole’ days are back.

One sector has gone “punch drunk” since March and deserves a closer look.

My favorite by far is betting against emerging market debt – the best performing fixed-income sector since 1992. Though it might be too early to wager against this booming asset class the payback will be spectacular once a Black Swan, or an unknown event, finally debases this formidable trend.

Over the last three years a host of emerging market economies have been the beneficiaries of credit rating upgrades by Moody’s, Fitch Ratings and Standard & Poor’s.

Only a decade ago many of these same countries were a basket case – including Russia, which defaulted on its foreign debt in 1998.

Driven by the bull market in raw materials this decade the emerging markets are now the flavor of the year as over 50% of stock market revenues in this sector are derived from natural resource exports – namely oil. Soaring commodities prices since 2002 have catapulted this asset class to the Big Leagues; this undeniable trend is confirmed by the famous acronym developed by Goldman Sachs earlier this decade – the BRICs or Brazil, Russia, India and China.

It almost takes an unlimited pool of capital or a lack of scruples to wager against the BRICs in 2009 – yet this Black Swan has a big payout should it materialize.