Britain’s top share index plunged on Monday to its lowest level in three weeks and fell back into the red for the year as fresh euro zone worries hit banks across the continent, while technical charts pointed to further weakness over the summer.

Euro zone concerns focused on Spain, whose ten-year sovereign bond yields spiked to more than 7.5 percent, a euro-era high, after a second region looked to be in line to apply for a central government bailout.

That drove fears Spain might become the fifth euro zone member in need of a sovereign rescue, spurred worries about the impact of further contagion to Italy and weighed on equity markets across the region.

Britain’s FTSE 100 closed at 5,533.87, down 117.90 points, or 2.1 percent, with no individual stock posting a gain. The blue chips are now down 0.7 percent for the year, going back into negative territory for the first time this month.

Even before Monday’s sharp falls, the FTSE 100’s closing Friday level had implied a contraction in earnings per share of 5.7 percent a year for five years, Thomson Reuters StarMine data showed, only slightly less bearish than the euro zone’s leaidng index of blue-chips, the Euro STOXX 50.

Volume on the FTSE was once again weak, at about two thirds of its 90-day daily average, which in turn helped fuel volatility and the FTSE Volatility Index ended up 19.7 percent.

The lack of volume probably makes it look much worse than it is. The only people trading will be sell-side, rather than buy-side traders, said Knight Capital strategist Ioan Smith.

UK banking shares were among the worst performers, dropping 3.3 percent in line with their European peers, as investors fretted about their holdings of euro zone sovereign debt as well as loan book exposure in the region.

News of a fresh ban on the short-selling of financials in Italy and a ban of the trade on all securities in Spain added weight to the afternoon selloff and could lead to further weakness for UK financials if demand to short them as a proxy increases.

If you’re a hedge fund and you’re caught short, you have to find another instrument that hasn’t been banned and sell out of your position or let it expire, a head of derivatives trading at a leading bank said.

HSBC Holdings, down 3.5 percent, was the biggest individual drag, taking about 13 points off the FTSE, as its share price neared a two-month low.

Meanwhile, heavyweight cyclical sectors energy and mining were among the worst performing sectors, shaving a combined 36 points off the index as concerns about the global economic outlook weighed on the price of oil and metals such as copper.

Russian steelmaker Evraz, down 7 percent, saw the biggest losses, as shares hit their lowest level since their full trading debut in London last November, with a cautious note from Morgan Stanley on the company adding to broad-based risk aversion.

EVRAZ’s plan to generate $5 billion of EBITDA in 2016 looks ambitious versus our (base case) estimate of $3.1 billion, strategists at Morgan Stanley said in a note.

Insurance company Aviva was also among the session’s worst performers, down 6.6 percent, while trading at almost double the volume of the index, after Bernstein cut its price target to 385 pence from 390 pence.

The sharp fall in UK shares could be seen as the beginning of a summer sell off, according to RBS technical analyst Dmytro Bondar.

There are quite strong seasonal patterns in equity markets. From the end of July until end of August the market tends to have corrections or a sell off. I think this is the beginning of this summer’s selloff, he said.

Overall the downward trend will go down to 5,250 where we can expect a bounce, and then continue to fall until the end of August probably to around 5,000.