Financial Select Sector SPDR (NYSEArca: XLF) was trying to break out to its highest levels since the 2008 subprime meltdown on Wednesday following quarterly earnings from banking bellwethers JP Morgan (NYSE: JPM) and Goldman Sachs (NYSE: GS).

The financial ETF has gathered nearly $1 billion in fresh assets recently amid fourth-quarter earnings reports from the largest U.S. banks. However, options trading in the ETF reveals that some institutional investors are cautious on the financial sector as banks trot out quarterly results. [Financial ETF Trading Picks Up on Bank Earnings]

“Given the sector’s notable outperformance to broad market proxies in the trailing one year period, it would make conceptual sense if holders of the sector ETF if not the underlying stocks in the financial sector are looking to lock in and/or protect recent gains,” said Paul Weisbruch at Street One Financial in a note this week.

XLF was a top sector ETF performer last year with a gain of nearly 30% as bank stocks shook off worries over the global economy, European debt crisis and U.S. deficit. [Financial Sector ETF Hits Highest Level Since March 2011]

The sector fund is trading right around $17 a share, which has acted as a strong resistance line in the wake of the financial crisis. [Financial ETF Near Four-Year High Eyes Breakout]

Goldman Sachs shares were up more than 2% after the company said its fourth-quarter profit nearly tripled from the year-ago period. Meanwhile, JP Morgan shares slipped about 1%. The bank topped quarterly expectations but further detailed the fallout from more than $6 billion in trading losses last year, The Wall Street Journal reported.

“The outsized, complex trades on credit default swaps tied to corporate bonds became known as the ‘London Whale.’ On Wednesday, the bank made public an internal report outlining mistakes and oversights by executives who played a role in the matter,” WSJ said.

XLF, the financial ETF, was flat in early trading Wednesday. JP Morgan is the fund’s largest holding at 8.4% of the portfolio. Goldman Sachs represents 2.9% of the ETF.

Financial Select Sector SPDR