Some robo-advisers go further than this by offering a service where they make decisions more regularly about customers’ investments. At Nutmeg, for example, clients can choose 'fixed allocation', where the client sticks with a set of assets that doesn’t change. But they can also opt for 'fully managed', where the investment team adjusts the overall mix of the investments within the product as regularly as once a month, if necessary, to reflect their views on what’s likely to go up and down. Or investors can plump for a variant of fully managed, called 'socially responsible', as well.

Nutmeg made the right call in early 2020 by going big on tech stocks in its fully managed and socially responsible products. These rose sharply as the pandemic made the world more digital. Robo-advisers differ from conventional wealth managers in two respects. The first is that the investments are, like highstreet suits, off-the-shelf rather than bespoke. The investor buys a particular product, and whoever buys that product has exactly the same portfolio. The second difference is that, even though they sometimes offer continuing asset allocation, robo-advisers mainly avoid the selection of particular stocks, or of funds whose managers act on their convictions by selecting particular stocks.

Twenty years ago, a widespread faith in active management would probably have prevented robo-advisers from making their mark, even if the enabling technology had been available. Now, conventional wealth managers still have responsibility for a lot more money than robo-advisers, but the latter’s market share is growing. They have benefited from a loss of confidence in active management, eroded by studies showing that, net of fees, active managers usually underperform passive managers.

This makes sense. If we assume that most of the professional investors who dominate any stock markets are reasonably competent and have access to more or less the same amount of information, why would one professional investor consistently outperform their peers? After allowing for their fees, which are higher than for managers of passive funds because more work is involved, it’s logical that the average active manager will do slightly worse.

Robo-advisers’ technological prowess also draws in investors. Conventional wealth managers have often relied on technology that leaves something to be desired. Mann gives a personal example. In early 2020, she wanted to move her pension from one provider to another. Because this required a ‘wet’ rather than digital signature, it involved sending a form to her mum, the proud owner of the de facto family printer, to print out. Mann’s mother then had to return it to her daughter to sign and send on.

Robo-advisers argue that their service is a lot more convenient for investors in many areas. As Mann puts it: “In just a small number of taps from your phone, you can add investments to your stocks and shares Isa and monitor your pension.”

Murphree says Wealthsimple does not advise on tax or trusts and acknowledges that conventional wealth managers have their uses. “People who have a complex set of circumstances will go for bespoke advice, which requires a different level of thinking and potentially multiple sources of expertise to resolve,” she says. Another point made by conventional wealth managers is that investing is often, or perhaps always, bound up with emotion. Investing became even more emotional in 2020, with people losing their jobs and investing their redundancy payments, pondering their long-term futures, and so on.

Conventional wealth managers argue that they are particularly good at navigating the emotional side because each client has an individual portfolio manager who often forms a close personal relationship with them. Sarah Waring, client and proposition director at Quilter, a large conventional wealth manager and financial adviser, makes an apt psychological observation. Investing is partly “about how to help people navigate emotions and behavioural biases, such as the urge to sell when markets are dropping and piling into stocks that are popular because of a fear of missing out”.

Her point testifies to what marks out retail investors: they are notoriously prone to buy when markets are at the top and sell when they are at the bottom – if left to their own devices. Some investors using robo-advisers may have reduced their returns by entering and exiting the market at the wrong times.

Cynics might argue that the very ease of access provided by robo-advisers could be counterproductive. Wealthsimple says one in three customers checks their portfolio every day. This suggests a less than long-term approach to their investments, which strengthens the argument that the steady-as-she-goes advice given by conventional wealth managers is important. In other words, robo-advisers have their virtues, but our own robotic addiction to our smartphones may not be great for our investments.