Aidon | Stone | Getty Images The S&P small-cap 600 index reached a new high Tuesday, as U.S. equities aim to close the first quarter of 2012 with their best performance since 1998 .

Similarly, the Russell 2000, another benchmark of companies with a market capitalization between $130 million and $2.97 billion, is trading 3 percent below its all-time high of 868.57. 

Within the S&P 600 index, 24 of its components are up more than 50 percent year-to-date.  While the index trades 3.2 percent above its 50-day moving average, 58 of the index's

constituents are up more than 12 percent over their respective moving averages — the most out of large or mid-cap companies. Below is a look at the top performing stocks in the index. _Ideas