The SPDR S&P 500 ETF Trust finished the month with a gain of 5.62 percent. The markets traded in a narrow sideways range last week, but that didn't hamper strong gains in February.

This weekend, Warren Buffett released his 50th annual letter to shareholders of Berkshire Hathaway Inc. This regular tradition summarizes the conglomerate's key financial statistics and offers insight into the future machinations and leadership at Berkshire.

Trading in Berkshire's stock next week has the potential to impact RevenueShares, which holds the largest allocation of any financial sector ETF to this single position. Berkshire makes up well over 13 percent of the revenue-weighted asset allocation in RevenueShares.

This ETF is re-balanced quarterly according to the most recent revenue data of the 83 underlying holdings that make up the portfolio.

First Trust Exchange-Traded Fund II

February automotive sales data is set to be released on Wednesday, which is likely to drive short-term momentum in CARZ. This fund tracks 36 global publicly traded automotive brands and has been showing signs of strength in recent weeks.

CARZ has now gained more than 8 percent in 2015 and is trading near 52-week highs. Better than expected sales data may be just what these companies need to breakout above their prior 2014 resistance level.

SPDR DoubleLine Total Return Tactical ETF

Last week marked the debut of Total Return Tactical, the first actively managed exchange-traded fund from renowned bond guru Jeffrey Gundlach of DoubleLine Capital LP. Industry experts will be watching the initial portfolio of bonds selected by Gundlach in accordance with his views on credit value and interest rate risks.

The active designation of Total Return Tactical allows the manager more flexibility to select well-researched areas of the global credit markets, rather than focusing heavily on an aggregate fixed-income benchmark