Independence could leave Scotland in a "financial mess" as it suffers the "wholesale relocation" of financial activity away from the newly independent nation, according to a research paper.
A report by Capital Economics predicts "significant capital flight" by banks, insurance firms and pension funds in the event of a Yes vote.
Analysts at the research company said it is likely markets are expecting a victory for the pro-Union side and have therefore "priced a No vote into UK assets".
There would therefore be a "fairly muted" market reaction to a No vote, with the potential for a wider "brief economic resurgence", they said.
In contrast, the report predicts there would be a "strong market reaction" to a vote for independence.
The report says: "The risk that an independent Scotland might get into a financial mess and, regardless of the formal currency arrangements, rUK (rest of UK) might feel the need to bail out the Scottish financial system, could prove to have a greater impact on gilt yields.
"The Scottish banking sector is equivalent to around 1,250% of Scotland's GDP, so the Scottish Government would not have the resources needed to stabilise the sector in a crisis.
"The high level of integration between rUK and Scotland's financial systems might mean that rUK felt that it had to help bail out the Scottish financial centre in the event of a crisis to prevent the crisis spreading to rUK's markets."
Analysts said uncertainty after a Yes vote could lead to a stronger sell-off of Scottish equities and "significant withdrawals" from Scottish banks.
The report said: "We would not be surprised if the Bank of England's contingency preparations, which (bank governor) Mark Carney highlighted two weeks ago, included capital controls on the Scottish financial sector to prevent a run on Scottish banks immediately after the referendum result was announced."
The three main Westminster parties have repeatedly ruled out the Scottish Government's preferred option of a formal currency union with the rest of the UK.
The analysts said that sterlingisation - or use of the pound without a formal agreement - would leave Scotland with no lender of last resort.
The report concludes: "Accordingly, following a 'Yes' vote, the wholesale relocation of financial activity, including banks, insurance firms and pension funds, seems likely.
"What's more, planned spending increases, an ageing population and falling North Sea revenues would put pressure on Scotland's public finances.
"So Scotland would need to increase taxes or cut other spending to prevent a ballooning deficit, with adverse impacts on the economy."
Chief Secretary to the Treasury Danny Alexander seized on the report as evidence that independence would lead to "unprecedented currency chaos and the potential loss of thousands of jobs in our financial services sector".
He went on: "The report also confirms what Alex Salmond simply won't admit - a separate Scotland would need to increase taxes or cut public spending to pay for independence.
"People are already filling out their postal ballots and we still do not have the answers to fundamental questions. The nationalists cannot keep Scots in the dark over their Plan B on currency. They are asking us to take a huge risk without giving us the facts."
However Tony Banks, chair of the pro-independence Business for Scotland network, said: "An independent Scotland will be one of the world's wealthiest nations, wealthier per head than France, Japan and the UK.
"Despite the scaremongering of the opposition, investment in Scotland is at record levels, second only to London and the South East, and with independence we will be able to attract increased investment to create new jobs in Scotland's economy.
"As the governor of the Bank of England set out recently, following a Yes vote the Bank of England will continue to be responsible for financial stability - and continuing to share the currency, which is both Scotland's and the rest of the UK's, in a formal currency union is in the best interests of both countries."