Arch Capital GroupArch Capital Group ( ACGL) is showing us an identical pattern right now. Like CCH, Arch spent most of this year in rally-mode, climbing around 20% to effectively double the returns that the S&P 500 has established in 2012. That upside gets threatened on the breakdown below $42.50 -- that's the trough that separates the two tops in this pattern. ACGL is another name that's got confirmation coming from momentum. 14-day RSI has been sloping lower for the last couple of months, right after signaling an overbought reading back in late October. There's typically a decent correlation between RSI and price since RSI is a derivative of price -- but note that while the two tops in price max out around the same level, the corresponding tops in RSI made lower highs. That's a big hint that this stock is losing its steam here.