Rob Burgeman, investment manager at Brewin Dolphin, said: 

The portfolio is completely invested in stocks, so Mr Davidson can expect a fair amount of volatility along the way.

Otherwise, it has a very nice balance. The largest holding – the Vanguard FTSE Global All Cap – offers a cost-effective exposure to global markets. It is partnered very well with Fundsmith Equity, a more actively managed option, which has delivered returns of 66pc in the past three years.

The Baillie Gifford British Smaller Companies fund has struggled somewhat over the last year. An alternative might be the ASI UK Smaller Companies fund. Run by Harry Nimmo since 1997. It has an excellent track record, gaining 106pc in the past five years.

The investment in Martin Currie Japan Equity is also worth reviewing. The fund is growth-focused and has lagged markets quite severely over the last year. JP Morgan Japanese Investment Trust is a possible alternative here.

There are a couple of gaps within the portfolio that I would address. Europe is home to some truly world- class companies – think of the French luxury goods company LVMH and the Dutch semiconductor maker ASML. Comgest Growth Europe ex-UK would be a good way to get exposure to this region; it has delivered 103pc in five years.

Mr Davidson’s holdings in RIT Capital Partners and Personal Assets – which together represent a fifth of the portfolio – provide some ballast in the event of market turbulence. But I would also look to add something like the JP Morgan Global Macro Opportunities Fund.