(Bloomberg) -- Shares in Ford Otosan are on a roll this week in a high-octane rally that has made Turkey’s largest automaker the most valuable stock on the Istanbul exchange.

Ford Otomotiv Sanayi AS, to give the joint venture between Ford Motor Co. and Turkey’s Koc Holding its formal name, is up 25% since Monday, heading for the sharpest three-day gain since 2008. It’s the best performer in the benchmark Borsa Istanbul 100 Index, overtaking Koc Holding’s leading market value in the process.

Turkish investors are no strangers to spectacular share moves, a phenomenon made even more common after thousands of retail buyers flocked to the market in the past couple of years. Trading in early 2021 has also been bolstered by foreign appetite for Turkish stocks, reflecting positive global sentiment toward riskier assets, and helping to fuel Ford Otosan’s rally.

In answers to questions, Ford Otosan cited its positive 2020 performance, increased clarity around government incentives for the industry, investors’ dividend expectations, news about the production of the electric Ford E-Transit, and optimism over “strong” exports as factors potentially drawing buyers.

That explanation alone may not be enough to convince some traders and analysts, who note that these supportive factors have been in the market for weeks. “There have certainly been positive expectations and developments, but the recent surge suggests some level of overpricing -- or there’s a bigger development that’s yet to be unveiled,” said Burak Isyar, head of research at ICBC Turkey Investment. “Valuations have started to stretch a bit.”

The 14-day relative strength index on the stock has risen to almost 84, well above the level of 70 that signals to some technical analysts that the shares may have rallied too hard and are poised to retreat, with the share looking the most overbought since 2010.

Among the 22 analysts who cover Ford Otosan, 13 have buy ratings, three rate the stock a sell and six are neutral.

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