Normally we think from day to day. Sometimes we think ahead a year. But in this article I want to think ahead 10 years, 20 years into the future.

World stock markets such as the FTSE 100 (FTSEINDICES: ^FTSE) and the Dow tend to have periods of famine followed by periods of feast. So, looking long term, the FTSE 100 might not go anywhere for 16 years, and then steadily climb over the next 16 years.

Investors need to sync with the zigzag

In this way, over decades and over centuries, the markets zigzag upwards. This is no more than the natural way things happen, in the same way that ripples flow outwards when you throw a pebble into a pond.

My view is that we are roughly at the end of the current stock market famine, though it is difficult to be precise about this -- the second ripple in the pond may not quite be the same height as the first.

What's more, I feel the current quantitative easing and rock bottom interest rates are distorting things, though just how is difficult to say. With interest rates predicted to be low for several years, and with the adrenaline of QE still coursing through the economy's veins, this will boost share prices. But will there be a crash, or at least a pullback, when QE finally ends? Who knows?

Plus there is the possibility of other events -- wars, Great Depressions, Great Deflations, etc. Sometimes the ripples meet a leaf floating in the water.

See you in 2030

If there is now a new stock market feast, just how high would the FTSE be at the end of this feast?

Well, if this new bull market matches the last great bull market (1985-1999), I have calculated that the FTSE 100 would reach 40 to 50,000.

However, things aren't quite the same now as they were in 1985. Then inflation was rampant, meaning share prices had fallen more, and would subsequently increase more as inflation was tamed. Whereas now inflation is low; and I expect it to remain low in the future. So I have reduced my guesstimate to 20,000.

When will this target be reached? I would say round about 2030. So, why don't you bookmark this article, and let's revisit it in 2030?

Mind you, I wouldn't bet any money on it....

Foolish final thought

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