Building, property and bank shares were hit hard yesterday as Sinn Féin emerged as the big winner from Saturday's election and staked a claim to a place in Government.
Shares in the country's biggest banks, AIB and Bank of Ireland, plunged more than 6pc, knocking over €700m off their value, while Cairn Homes slumped more than 8pc, with Glenveagh down over 8pc and Ires Reit off by almost 7pc.
Sinn Féin wants to increase the bank levy to €200m from €150m and end banks' ability to use crash-era losses to shelter current profits.
It also has radical proposals to expand State provision of housing, while imposing a rent freeze, and to increase stamp duty on non-residential property deals.
Other proposals include banning the sale of non-performing mortgages to vulture funds and to give the Central Bank the power to cap mortgage rates.
"For now, I'd say that this is mostly likely the initial reflection on a relatively surprising outcome," Bert Colijn, ING's senior economist for the eurozone, said of the market reaction to Sinn Féin.
"There is a long road to go for a government, and coalition talks will be hard regardless of the partners involved. If a government would involve Sinn Féin, it's therefore too early to conclude that their housing market plans would see fruition," he said.
The bond market, however, took the news in its stride, although the spread for Irish 10-year bonds over their German counterparts - a measure of the cost demanded by investors for holding Irish debt versus the rock-solid German credit - did tick modestly higher.
With the budget in surplus and GDP still growing strongly, albeit with the risk of a trade hit from Brexit, Sinn Féin's impact on the near-term prospects for the economy and State finances appears limited.
Even if Sinn Féin's policies caused a sharp decline in house prices, this would not spell disaster in the same way it did a decade ago, as valuations are not as stretched and household debt is a third lower than at its peak.
Further out, however, it could have a much bigger impact on State finances. "The first is that the increased influence of SF means that Ireland runs much looser fiscal policy, which could lead to concerns about debt sustainability," said Jack Allen-Reynolds, senior Europe economist at Capital Economics.
"The second is that there is a serious push for Irish reunification… If unification ever took place, it could put a huge strain on Ireland's public finances."
Estimates of the cost of Irish unification are disputed. Sinn Féin said in a 2016 document that it could cost as little as £2.7bn (€3.2bn), although the party's estimate was adjudged "false" by EUFactCheck, the fact-checking project of the European Journalism Training Association.