ZURICH/LONDON (Reuters) – Tidjane Thiam starts work as CEO of Credit Suisse (CSGN.VX) next month with investors optimistic he can bring about a major change of strategy at the bank, even if he has to raise cash to do it. An expectation that the 52-year-old will successfully switch Credit Suisse’s focus to lucrative Asian wealth management and shrink its cash-intensive investment bank has propelled the Zurich-based lender’s shares around 12 percent since Thiam’s appointment was announced in March.