Trading in Teradyne, Inc. TER is quiet on Tuesday. This follows yesterday's gain of almost 13%. Analysts attribute the move to a brokerage upgrade.Some traders are watching Teradyne for a potential trading idea. This is why it is our Stock of the Day.Some price levels have more importance than others. This is a fundamental and important principle of the financial markets.Traders refer to these levels as support and resistance levels.If there are more shares of a stock for sale than there are to buy, the pri ...