ZURICH (Reuters) – Temenos lost a fifth of its value on Friday after the Swiss banking software group ditched its full-year guidance and reported a steep fall in third-quarter profit. The share plunge in early trading wiped 900 million Swiss francs ($902 million) from its valuation after investors and analysts reacted to its profit warning on Thursday. It was also by far the biggest faller among European tech stocks. Temenos said it now expected 2022 operating profit to fall by 25%, saying banks’ decision-making had turned cautious while its costs were rising. The company, which shook up its s…