Hands up if you’ve sat on the stock market sidelines since March, waiting for a seemingly short-term surge in equity markets to peter out. Mmm; that’s quite a few.

Lots of investors remain marooned on the sidelines, looking increasingly more like sporting substitutes unlikely to be used, yet convinced they will make their killing when the market next plummets. They may be right — no-one can tell.

Frustratingly for these Crusoe-esque souls, the £10.2bn offer by Kraft Foods for iconic confectioner Cadbury’s provided the FTSE100 index with fresh impetus as Cadbury’s share price rose by almost 40 per cent, thereby ensuring City computer screens remained predominantly green, as they have done since early spring.

Meanwhile, there are all sorts of theories about the recent rally.

Some attribute the market’s buoyancy to fund managers’ willingness to emulate Warren Buffett and snap up high-yielding, high-quality assets when they looked incredibly cheap.

“Volatility,” suggested another analyst, “is the market’s way of getting rid of idiots”, as though “the market” was a living, breathing entity capable of saying: “There’s far too many dopes with cash invested here. Let’s shake ‘em up.”

Such an approach suggests that non-idiots, presumably those for whom the emperor’s new clothes has a certain sartorial appeal, are capable of timing their re-entry to equity markets, though this is, of course, absolute nonsense.

This is not to say that investors should be bereft of a portfolio strategy whereby they determine which markets are likely to rise more than anticipated, and others less than expected, and amend their mix of equities (and other assets) accordingly.

Such action is completely different from dramatic switches between stocks to cash and vice versa.

In his excellent The Only Three Questions That Count, Ken Fisher warned: “Never forget how fast the market moves.

“Your annual return can come from just a few days of big moves. Do you know which days those will be? I sure don’t and I’ve been managing money for over a third of a century.”

Fisher’s succinct advice should alert the ‘investment subs’ to abandon the sidelines, while for those who believe they can hop in and out of the market as though it was an investment-style garage where you can periodically replenish your cash reserves, if the folly of such action does not act as a deterrent, then the costs should.

Trying to ‘time the market’ is not a costless exercise. If it was, everyone would attempt it because getting it right can generate enormous returns.

For a start, there is the opportunity cost. By constantly switching from shares to cash and back again, you could miss the periods when the market suddenly surges.

There are also additional transactions costs to be incurred, while such a strategy can also increase potential tax liabilities.

Accurate market timing is the investor’s holy grail, but even those who claim to have successfully timed their return (or exit) cannot explain the large chunk of luck they enjoyed when either getting out, or back in just in time.

Those sidelined souls should bear this in mind when next contemplating whether to dive back into the stock market and acknowledge the benefits that accrue from maintaining a longer-term presence in equities.