Don't be fooled by the 30% premium on shares that $40 billion bank PNC Financial Services Group ( PNC) commands today; the stock is starting to look "toppy" in the long-term here. >>5 Stocks Insiders Love Right Now PNC is currently forming a double top, a bearish reversal pattern that's formed by two swing highs that top out around the same price level. The sell signal comes on a break below the trough that separates the two tops. For PNC, that support level comes into play at $70.50. If shares slip below that $70.50 level, we've got a sell signal. Momentum, measured by 14-day RSI, adds some extra confidence to the topping setup in PNC. In the context of the long-term move, a drawn-out downtrend in RSI is still very much intact right now. Since momentum is a leading indicator of price, that's a signal that buying pressure is waning in shares of this big bank right now. Still, downside isn't a foregone conclusion until $70.50 gets violated.