How long did it first take for the FTSE 100 to double? And with it passing 10,000 for the first time in January 2026, how long might we wait for it to double to 20,000 and beyond?
From the first days of the FTSE 100 (in 1984 when it began on 1,000), it took just three years before it hit the 2,000 mark. But it’s unlikely we’ll see London’s leading index jump 100% by 2029.
The future is unpredictable, of course. That’s why I roped in everyone’s favourite hallucinating chatbot, ChatGPT. I asked it: “When will the FTSE 100 hit 20,000?”
The answer
ChatGPT quickly responded that it was “far off” and that a date in the 2030s or later was on the cards. Here was the most relevant section of its reply: “Long-term statistical or algorithmic models (like those on some forecasting sites) show the index perhaps approaching 19,000 only by 2037, and even that depends on sustained, above-average returns every year.”
There was something missing from all this analysis – which yet again was a reminder that these AI tools can’t be used as financial advice – which was the complete absence of any mention of dividends.
The FTSE 100 is perhaps the biggest dividend-paying index in the world. On top of share price gains, investors have come to expect in the region of 4% a year on average paid as as a dividend yield (although it’s a little lower at the moment).
The points tally doesn’t take into account these dividends, of course, only share price moves. Therefore, if we were to factor in the chunky payouts from some of the Footsie’s world-class dividend stocks then enthusiastic investors might make the 20,000 mark arrive a lot sooner.
Cheapness
Another oversight from ChatGPT was the lack of any mention of valuations. Compared to indexes in other countries, the FTSE 100 is crammed with low price-to-earnings ratio stocks. Take easyJet (LSE: EZJ) for example, which trades at a P/E of only 7.7. A shift in these kinds of valuations could bring that 20,000 target along much faster.
Of course, the best way to take advantage of undervalued stocks is to buy shares in individual companies rather than an entire index. Airlines like easyJet are in one area I believe could be cheap at the moment. Its share price is still 47% cheaper than it was before the pandemic.
It’s worth mentioning that the battered share price highlights some of the risks here too. The knock to investor confidence from the pandemic era when planes were grounded didn’t help the low-cost airline. But since then, fuel costs, wage costs and general inflation issues have been squeezing margins too.
Still, single-digit P/E ratios are thin on the ground these days. And with earnings forecast to rise and bring the P/E down to 6 in 2027, I’d say there could be enough value here to make easyJet a stock worth considering.
The date
For a bit of fun (and not to be taken at all seriously), I pushed ChatGPT for a date. It gave me a “pub-bet answer”. It said: “FTSE 100 at 20,000? September 2043. If it happens earlier, drinks are on the bulls. If later… well, that’s the FTSE being the FTSE.”
