The second step up followed when Warren Buffett's Berkshire Hathaway (NYSE: BRK.A) (NYSE: BRK.B) invested $4.1 billion in Taiwan Semi's stock. Investors had feared a much gloomier result based on "flattish" sales guidance in mid-October's third-quarter report and a 4.5% sequential downtick in September. At the same time, that-morning's inflation report showed that the consumer price index (CPI) rose just 0.4% in October -- the smallest increase since January.