The platform surveyed 1,500 of its clients, with around 25 per cent saying the referendum result on in June 2016 has had a negative impact on their investment portfolio since.
The other 75 per cent said it was either a positive or had no impact.
The most bought share by clients of the platform, not just those surveyed but all clients, over the past year include Lloyds Banking Group, which derives almost all of its revenue from within the UK.
Prior to the referendum result being announced, 86 per cent of Share Centre clients surveyed said they expected a vote for the UK to leave the EU to be negative for their portfolio.
But since the result of the referendum was announced on the 24 June 2016, the FTSE 100 has soared around 25 per cent, though the majority of the earnings of FTSE 100 companies - around 75 per cent - come from overseas, rather than the UK, meaning they are likely to be insulated from domestic hits to revenue or have benefited from a weak sterling since the vote.
Richard Stone, chief executive of the Share Centre, said: "For most personal investors rising markets since the referendum result have driven portfolio values up and generally improved sentiment.
"It is certainly the case that personal investors’ fears of the impacts of a vote to Leave on the stockmarket have not materialised.
"However, fear has not gone away with a majority expecting a negative impact on markets as the leaving date approaches and over a third looking to alter their investment behaviour as a consequence."
Mr Stone said this level of opinion reinforce his view that markets will be more volatile over the months ahead and will be more prone to movements driven by sentiment and reporting of the latest twists and turns of the Brexit negotiations.
But he said the fundamental global economic position remains positive and for public companies this should drive higher earnings and ultimately improved valuations.
"There remains a substantial amount of liquidity in the financial system and this will, in our view, act as a cushioning mechanism to any volatility. Indeed, we saw this in February when markets fell but then rebounded only to go on to set new record highs,” he said.
Margaret Lawson, who runs the £200m SVM UK Growth fund, said her approach is to find companies that are not exposed to economic events. This has led her to avoiding banks because of the level of debt those businesses have, and avoids companies such as miners which are cyclical.
Azad Zangana, chief european economist at Schroders, said he expects the UK to experience “stagflation” for some time to come.
This is a condition where growth is low at around, in his view, 1.4 per cent, while inflation remains high. Typically inflation and GDP growth move in the same direction, but in Mr Zangana’s analysis the weakness of the currency creates high inflation, but also restricts consumer spending and so GDP is low.
The UK has a current account deficit, this means it pays out more to other countries for imported goods than it receives for UK exports. This is funded in the UK by inflows of foreign capital into UK assets, such as government bonds and UK-listed shares, as well as investments by overseas companies into UK subsidiaries.
Mr Zanagana said this type of investment has dropped starkly over the past year, as such companies are now “preparing for the worst” from Brexit.
David.Thorpe@ft.com
