This special situation results from recent forced selling due to delisting from Australia and New Zealand exchanges.
Long investors in Coats Group (listed in London Stock Exchange) stand to make 10%+ if prices revert to back to previous 30p/share vs current GBP 26p/share.
Until recently Coats was listed on 3 stock exchanges - London, Australia and New Zealand. This did not make much sense and company delisted from Australia and New Zealand on the 24th of June. All outstanding Aussie and Kiwi shares were converted 1:1 into UK listed shares. Naturally this caused forced selling in advance of the event by institutional/retail investors in Australia and New Zealand who are not allowed or not willing to hold foreign shares (on May 19th, 11% of share were outstanding in those exchanges). And this in turn led arbitrage trades push down the share price in UK as well. One can see this by following daily moves in all 3 exchanges, most of which occurred right before 22nd of June - last trading day in Australia and New Zealand.
Stock in Australia https://www.google.com/finance?q=ASX%3ACGW&ei=K1xyV8iaGcLLswGnrozYDQ
Stock in New Zealand https://www.google.com/finance?q=NZE%3ACOA&ei=SGNyV8E-gfGyAZLwjqAN
Upcoming Brexit vote likely added to the share price pressure although company is hardly effected due to sales/costs being international (Coats is world leader in thread manufacturing).
I expect fast rebound to the previous share price levels around 30p.