The world’s first robots-themed managed equity fund has, less than a year since its launch, proved an unlikely hit with “Mrs Watanabe”, the typically ultra-conservative investor of Japan’s household savings.

The uncharacteristic bet — a wager on a global portfolio of large- to micro-cap stocks that envisions a vague future-scape of self-driving cars, helper automatons, artificially intelligent drones and human-free factories — has paid off.

Since its launch on August 31 last year, the Nikko Asset Management (NAM) Global Robotics Equity Fund, has gained just 0.6 per cent. But it has done so against a background of rapidly diminishing confidence in Japan’s Abenomics revival programme and slumping domestic shares. The Nikkei 225 Average — the benchmark against which retail Japanese investors tend to judge success — has fallen more than 17 per cent over the same period.

The robotics fund’s assets are divided roughly in thirds among the US, Japan and Europe, with its top holdings the Japanese factory automation group Keyence and US-based Rockwell Automation. It represents a portfolio of 41 stocks from what its managers say is a potential universe of about 500 equities worldwide.

Launched with assets of about $1bn, the fund has swelled to nearly $5bn. The surge has been driven by retail investors lured, in part, by the prospect of a yen-based fund that diversifies them into at least six other currencies including the dollar, euro and Swiss franc.

“When we originally thought up this fund, we thought this was going to attract young, male investors. Actually, our distributors are telling us that women and older investors are buying strongly,” said the fund’s creator, Naofumi Chiba. “You have to remember that Japan is a country where people feel very familiar with robots.”

Predictions of the size of the global robotics and automation markets vary widely but Bank of America Merrill Lynch in a recent report forecast a $153bn global robot and AI market by 2020, with $14tn-$33tn in combined cost reductions in manufacturing and healthcare, cuts in employment costs and other efficiency gains. By 2025, according to BAML, robots could be performing 45 per cent of manufacturing tasks, against about 10 per cent now.

Japanese investors, Mr Chiba said, can see not only that the likes of Google, Amazon and Facebook are pouring money into robot companies, but they can also already see the effects of a shrinking population at home.

The fund’s outperformance, say analysts, may have far-reaching effects on the investment industry, increasing pressure to more permanently establish the idea of a “robotics sector”. The fund was conceptualised more than two years ago but the idea was rejected by almost every manager Nikko approached, Mr Chiba said.

The proposed theme was broad — ranging from healthcare to power plant automation — and the Global Industry Classification Standard (GICS) does not recognise a robotics sector that potentially cuts across so many industries. Lazard eventually agreed to manage the fund, presuming, according to Nikko, that it would appeal strongly to Japanese retail investors.

Nikko’s concept was the first managed fund of its type. In 2013, the Robo Stox Global Robotics and Automation Index tracking 77 global stocks was established as a Nasdaq-listed exchange-traded fund.