Nikkei up on short-covering; market on edge before central bank meetings, Brexit vote
* Volatility spikes to 3-month high on Brexit concerns
* Short-sell ratio stays above 40
* Immediate support level seen at 15,600 - trader
By Ayai Tomisawa
TOKYO, June 15 (Reuters) - Japanese stocks rose in choppy trade on Wednesday morning, snapping a four-day losing streak thanks to short-covering, but the foray into positive territory is expected to be short-lived on worries Britain might vote to leave the European Union.
The Nikkei share average opened lower, but then headed higher to be up 0.8 percent at 15,983.88 in midmorning trade. The index closed at its lowest level since April 12 on the previous day.
Reflecting the underlying bearish sentiment, short-sell ratio has remained above 40 since hitting a record high on Friday when volumes rose with the futures and options settlement on that day.
Exporters bounced on short-covering after being heavily sold recently. Toyota Motor Corp rose 1.1 percent, recovering from more than a two-month low, while Honda Motor Co gained 0.6 percent after falling to the lowest level since December 2012.
Recently battered financials also gained some respite, with Mitsubishi UFJ Financial Group rising 0.8 percent and Mizuho Financial Group advancing 0.6 percent. Continuación...