Interest rates have just turned from a headwind into a tailwind.It finally happened. The Federal Reserve just lowered interest rates by 50 basis points (0.5% in percentage terms). Investors rejoiced, sending the S&P 500 to new, all-time highs. The stock market is now up 100% during the past five years, driven by rising earnings ratios and the artificial intelligence (AI) boom despite the Fed taking interest rates from zero to 5% two years ago.Not every company is at all-time highs, though. Enter Ally Financ ...