By the time a theme takes hold any chance of getting in on the ground floor have passed and, at best, those attracted can make a profit before the mood passes and latecomers are left with crumbs.

Right now the cautious mood, reflected in enthusiasm for bonds has already pushed up prices alongside those of "boring" stocks, such as utilities, which have become expensive relative to the market as a whole. So latecomers to the current theme of safety first are likely to be disappointed, as they will be if they have opted for the "safety" of precious metals where prices have already turned down.

Those seeking greater excitement in the equity markets need only look back to the '90s when anything labelled "dotcom" seemed a sure-fire way of making money until that bubble burst with a vengeance.

One person who was unfazed by this development was investment manager Warren Buffett who had been criticised as a dinosaur for staying away from dotcom stocks. As a result his funds considerably underperformed the market but surged back after the collapse of the dotcom bubble in 2000.

Buffett has ignored more fads and trends than most of us are even aware of. In the '60s, during another bout of overenthusiasm in stock markets celebrating shares with unprecedented growth rates, Buffett said: "We live in an investment world populated not by those who must be logically persuaded to believe, but by the hopeful, credulous and greedy, grasping for an excuse to believe."

Investors have always looked for things to believe in, be it the endless expansion of the railway system in Victorian Britain or the roaring twenties when investors heralded a new consumer age of cars and radio sets that would yield endless profits. This belief held good right up to the 1929 Wall Street crash.

Closer to home we have had successive Asian market booms based on a theme of, first, Japan taking over the world, which seemed plausible until the Japanese crash at the end of the '80s, followed almost exactly a decade later by the idea that East Asia's growth was unstoppable as it became the manufacturing workshop of the world and home to new financial markets in places such as Hong Kong and Singapore. That dream was abruptly shattered in 1997 when the Thai market collapsed and, like dominoes, markets nearby tumbled.

What has changed over the years is not the gullibility of investors, nor a disillusion with new themes, but the time span of both booms and busts. Don't forget it took almost three decades for the Dow Jones index to regain the highs reached by the stock market boom in 1929. But in the case of the Asian markets (but not Japan) recovery from the 1997 crash took no more than five years. Twelve years after the dotcom crash, the biggest IPOs are again coming from that sector, and while some have made good - that would be Google - the more recent Facebook flotation looks rather different.

The one theme that does not change is that of quality. Stock market fads may drive counters up and down with great speed but, over time, quality will out. This means focusing on companies that produce consistently good returns, manage their finances well and show an ability to grow - usually organically. Companies in Hong Kong that fall into this category include Café de Coral, Techtronic Industries and Hang Seng Bank - not sexy investments but sound.