Industry figures have reacted to a "curve ball for markets" as the UK votes to leave the European Union.
In yesterday's referendum, the 'leave' campaign won by 52% of the votes to 48%.
The shock decision has caused sterling to fall by more than 10% to trade at $1.338, down from $1.487 yesterday.
Experts have suggested the decision could lead to several years of uncertainty and instability, for UK assets.
Toby Nangle, head of multi-asset asset allocation, Columbia Threadneedle
"We lack a clear vision of what future relationship the United Kingdom will have with its largest trading partner, the timescale of the exit, and the configuration of the domestic party political landscape after a brutal campaign.
"At open we anticipate that fixed income markets will jump to price a UK recession and a Bank of England rate cut, although the scale of currency weakness means that inflation pass-through will be carefully watched as the MPC have indicated that they will not cut and may indeed hike if inflation expectations become unanchored.
Piers Hillier, chief investment officer, Royal London Asset Management
"On the back of this morning's result we expect the UK will fall into a recession. Unfortunately I see unstable market conditions lasting for between three and five years while new trade agreements are drawn up.
"It is our view that the UK government will be left with no choice but to stimulate the economy through fiscal and monetary means, flooding the system with liquidity if necessary."
Neil Williams, group chief economist, Hermes Investment Management
Williams described the decision as a "curve ball" for markets but said he expected the UK economy would survive.
"The UK economy will of course 'survive', given its entrepreneurial flair, increasing focus on non-EU trade, and likely policy accommodation by the Bank of England and UK Treasury.
"However, getting to the next stage looks a long, drawn-out 'can of worms', leaving considerable uncertainty for UK assets and markets. The extent of this damage now rests on the manner of the exit."
Stephen Bailey, fund manager in the Liontrust macro-thematic team
"We have considerable US dollar exposure in our portfolios and while this is not a Brexit-driven position, we believe it should provide protection in the event of a drop in sterling.
"We believe the vote to leave could cause the sterling/US dollar exchange rate to correct by around 10% and would act to hedge our position if we see a 1.30-1.35 level.
"In terms of equity markets, we believe the UK could come off by around 5% but stress that we see any market and currency implications of Brexit as short term and do not expect any long-term damage."
Matthew Beesley, head of global equities, Henderson
"With the BBC calling the result at 0439 for leave, markets are, not unsurprisingly, reeling. With currency and stock markets rallying so aggressively over the last week, with 'cable' (USD-GBP) having touched 1.50 as the polls closed, the investor shock today will be hard to digest. We estimate markets were pricing in around only a 20% chance of Leave.
"At the time of writing, Asian markets have not responded as negatively as we might have expected. The -8% fall that is currently reflected in FTSE futures could be just the start of an elongated period of weakness for the UK and indeed European stock markets. While sterling and the euro have led overnight in constantly trading markets, stock bourses will follow at 8am.
"There will be debate and uncertainty over what exactly will happen next: how quickly will the UK evoke Article 50? What does the UK economy look like outside of the EU?
"Will the United Kingdom stay United or will this trigger a break-up of the United Kingdom as we know it, with another independence vote for Scotland given the country's overwhelming vote to remain?
"Could this give rise again to structural questions around the future of the European Union given the succour the outcome will give to other disgruntled factions across the continent.
"For the UK, this is a seismic result. Its implications will undoubtedly be felt beyond UK borders, with immediate and perhaps long-lasting impacts on global trade and certainly on all asset markets."
Paras Anand, head of European equities, Fidelity International
"The vote by the UK electorate to leave the EU has certainly taken both the currency markets and stock markets by surprise. It is important to recognise the scale of moves that we are seeing are in context to a strong performance both by sterling and by UK markets over the last week.
"While the result will lead to political uncertainty, which may lead to shorter term volatility in the markets, it is important to remember that such events impact the long-term prospects of companies only at the margin.
"The consequence of the vote on the UK domestic economy and Europe more broadly is difficult to call and will likely only be evident over time. But the fall in the currency increases the competitiveness of those sectors exporting both goods and services internationally and should increase the appetite for inward investment over time.
"If we look at the corporate sector in particular, we are in an environment where companies are holding significant cash balances and the scope for ongoing corporate activity remains. This should limit the extent of the falls that we should see over the coming weeks and months."
Arif Husain, head of international fixed income, T. Rowe Price
"Those who believe Brexit is a UK problem are misunderstanding the impact it will have globally. They're forgetting the impact that Greece had – and Greece is much smaller than the UK, and not a financial centre.
"The vote to leave could result in a global recession. It's likely that the chances of a global recession have risen above 50%. For investors, the money was to be made in the run-up to the referendum from all the volatility that was occurring. It will be harder to make money now.
"No doubt this will be the first of many volatile trading sessions, and the major central banks are standing by to intervene if necessary. But we caution against reacting as though this were a second 'Lehman moment', as some commentators have suggested."
Neuberger Berman investment team
"The likelihood of at least medium-term damage to the UK economy from a 'Leave' vote, as well as pronounced market volatility on the back of political uncertainty for the UK and the EU as a whole, did lead us to adopt a relatively neutral stance in portfolios coming into the vote.
"But we positioned neutrally not only as a buffer against volatility, but to ensure investors were in a position to take advantage, potentially by adding to riskier-assets based on a longer-term view of fundamentals.
"Still, the UK has chosen the rockier of two paths. It piles up the political distractions that have dogged the administration of Prime Minister David Cameron and Chancellor George Osborne.
The 'Brexit' camp are clearly in the ascendant, but the vote revealed a lack of national consensus. And even consensus would not wish away the complexity of this exit, a 'monumental', multi-year task in the words of one legal expert.
"That is likely to prolong the period of low corporate investment we have seen leading up to the vote, both within the UK and in the form of foreign direct investment. This, together with the higher costs of trading, is what led mainstream economists to forecast a 3-7 percentage point negative long-term impact on UK GDP.
"The pain may not be felt evenly. Many of the large companies in the FTSE 100 Index are global rather than UK businesses – 80% of the index's revenues come from overseas. This insulates them from any domestic downturn and potentially delivers a windfall from the weakened pound.
"Smaller, more domestically-focused companies are more vulnerable to a fall in consumer demand and higher import costs. That could be a source of opportunity during a sell-off in UK assets, particularly if the UK makes its new status work over the longer term.
"Elsewhere, the economic impact is likely to be felt most keenly in Europe and, in the words of one Federal Reserve Bank President, to have only 'moderate direct effects on the US economy in the near term'. Again, we expect an excessive market reaction to be a potential source of opportunity."
Darius McDermott, managing director, Chelsea & FundCalibre
"This is a defining moment in our history – not least because the polls were right and the bookies were wrong! In terms of stockmarkets, we could be in for a few difficult hours, days and months. Buckle up. It could be quite a ride.
"Markets will now look to our politicians to see how they will deal with the situation – what plans they have to make this work. Also crucial will be the Bank of England's response to huge moves in the pound. We don't want knee-jerk reactions from Parliament. What we actually need is for our leaders to be sensible, rational and show us some stability.
"So markets are likely to be volatile in a general downward direction for a while, not helped by the fact that there are other big issues in the world that could also have an impact: China slowing, the US election and now possible contagion of Brexit to Frexit, etc.
"But the world won't end. And as we know from quite recent experience, markets bounce back and good companies continue to thrive in the longer term. I would actually even be tempted to buy into the market dips – not huge amounts, but small lump sums."
Mark Posniak, managing director, Dragonfly Property Finance
"There will be a huge amount of hypothesising about the fate of the UK property market, but it's impossible to know the full ramifications of the leave vote.
"How the Bank of England, the government, the financial markets and economy react today and in the weeks and months ahead will be crucial to how the property market performs.
"Caution, reduced transaction levels and downward pressure on prices in the months ahead are almost certain but we should not write off the property market.
"Despite the magnitude of the result, the structural supply issue underpinning the UK's property market may well prevent prices falling materially. Overseas demand may also increase on the back of the decimated pound. For many overseas investors, buying British property just got a lot cheaper.
"Short-term liquidity issues are possible, if not likely, among bank lenders and non-bank lenders that have bank funding lines. In the days and weeks ahead, banks and every other type of lender will be monitoring events forensically.
"With leave winning the referendum, the appetite for risk will almost certainly reduce until we have a better understanding of what we're facing."
Adrian Lowcock, head of investing, AXA Wealth
"There is no doubt a leave result is going to provide more uncertainty and therefore volatility in markets in the coming days and weeks. The impact of a leave vote will weigh on the UK much longer than a remain vote ever would. The UK stock market is likely to have a Brexit discount for sometime, as our politicians negotiate with the European Union.
"Times of uncertainty will knock investor confidence as they see falling share prices and panicked experts predict doom and gloom. This leads to making quick and often irrational decisions, such as selling after the market has fallen.
"Investors need to remember that, in the short run, markets overemphasise the importance of current events while they barely register over the long run as markets revert back to fundamentals. Companies will adjust and the British economy will adapt.
"Investors need to look through all the noise and remain focused on their personal goals. Any sell-off will produce opportunities for prudent investors looking at the big picture and focused on the longer term.
"A weaker sterling will help the UK become more competitive and could boost the earnings of many of UK's large companies where the bulk of profits are made overseas."
Charles Hepworth, investment director, GAM
"The UK's decision to leave the EU has come as a surprise, given recent polls. We now expect sterling to weaken considerably to nearer parity against the euro and the 1.20 region against the dollar.
"Looking at the UK equity market, we expect some reasonably large declines in prices of between 15-20% over the next few months. UK growth downgrades of up to an annualised 1% drop in GDP over the next decade is highly likely, with the greatest impacts being seen over the next few years. European equity markets will also come under severe pressure on the perceived fracturing of the EU.
"Should UK equity exposure be required for specific client mandates, then relative safety could be found in the larger cap end of the market, but expect mid and smaller-cap companies to come under significant pressure. A risk-off mode to European equities in general would be the most prudent option at this time."