Mr Gergel said exchange traded funds (ETFs) and other passive investment products have responded to the heightened level of political uncertainty in the UK by blindly selling off all parts of the market, including companies that are performing well.
Mr Gergel said: "The rising popularity of ETFs and index tracker funds, which allow investors to take asset allocation decisions on entire markets may have led to indiscriminate selling of the whole market.
"Whilst some UK stocks will undoubtedly face difficulties as a result of Brexit and potential loss of access to the single market, there are a large number of UK-listed companies which draw the majority of their profits overseas and will face almost no impact from the loss of Britain's EU membership.
"This trend of investors exiting the UK market has been further exaggerated by certain investment strategies which sell underperforming asset classes. We believe that 'basket trades' are missing some of the excellent opportunities for stock picking that the environment has created.
"We believe that the direct impact of Brexit on UK listed companies will be limited. That is not to say that there are not challenges facing the UK economy, but it is crucial that investors understand that UK listed companies (especially those in the FTSE) are not representative of the wider economy.
"When we look at stocks, 19 per cent of the UK market is oil and mining, 7 per cent is pharmaceuticals, 10 per cent is consumer goods, all of which have make relatively limited exposure to the UK economy.
"Conversely, car production in the UK is at a 30-year high, and contributes heavily to the UK economy, but there is not a single listed car manufacturer on the London stock exchange.
"If the global economy continues to grow, the operating performance of internationally focused stocks should remain strong."
He said UK equities trade at an average price to earnings (P/E) multiple of 13, while global equities trade at a multiple of around 18 times earnings.
Mr Gergel said the negative impact of Brexit is already reflected in the valuation of many UK companies, he particularly cited Land Securities, a UK property company that, he said, trades at a discount to the value of its net assets of 40 per cent.
This means the market capitalisation of the company is lower that the value of the assets owned by the company, according to the accounts.
Mark Barnett, head of UK equities at Invesco Perpetual, said he is also keen on UK property companies, because when those companies actually sell the assets, they get a price higher than the value in the accounts, despite the share prices implying the value of the assets will be less.
Justin Onuekwusi, multi-asset fund manager at Legal & General, is keen on property company shares in the current climate, but said he is avoiding UK property shares.
He said that while UK property companies do trade at a discount to net asset values, "the reality is no one knows what will happen to UK property after Brexit, we know there will be an effect, but we don't know if it will be a major effect or not.
"But because we don't know what the effect will be, we don't know what value the assets should have."
Mr Gergel added that domestically focused shares in areas such as banks may also be a bargain as they generate the bulk of their returns from within the UK domestic economy, and do not rely on European trade.
Philip Milton, who runs Philip Milton & Co, an advice firm in Devon, said it is obvious that the UK market is cheap, and the US market is expensive in valuation terms, and he doesn't view Brexit as a negative for the economy.
david.thorpe@ft.com
