Things have been less auspicious at Vishay Intertechnology ( VSH) lately. Shares of the Pennsylvania-based semiconductor stock have moved up a whopping 2% in the last 12 months, trailing the broad market's ascent by around 12% over the same period. But that underperformance could be coming to an end thanks to a reversal pattern that's been shaping up in shares over the long term. Vishay is currently forming a double bottom, a price pattern that's formed by two swing lows that bottom out at approximately the same price level. The two bottoms are separated by a peak that marks that resistance level for the setup. A breakout above that price -- right at $11 for VSH -- is the buy signal for shares. Because the setup for this pattern has been longer-term, the trading implications are longer-term as well. That means that once Vishay is finally able to push through $11 (its most recent attempt wasn't successful), the rally could last a while. Still, remember that sellers own the space at and above $11 right now, that's why it's imperative to wait for the breakout before you buy.