The earnings season is off to a flying start with equity markets scaling record highs, owing to a slew of upbeat economic data, strong corporate performance and President Donald Trump's tax reform proposal. However, the performance has been a mixed bag for biotech companies, with some beating market expectations, while a few failing to do so (read: U.S. Fiscal Deficit at 3.5% of GDP: ETFs in Focus).We will now discuss the performance of a few biotech giants such as Amgen Inc AMGN, Gilead Sciences GILD, Biogen Inc BIIB and Alexion Pharmaceuticals ALXN (read: Should You Keep Your Portfolio Healthy with Biotech ETFs?).Earnings in FocusAmgen reported third-quarter 2017 adjusted earnings of $3.27 per share on Oct 25, 2017, surpassing the Zacks Consensus Estimate of $3.09 and increasing 8.3% from $3.02 per share in the year-ago quarter. The company also beat the Zacks Consensus Estimate on the revenue front. Amgen reported revenues of $5.773 billion, surpassing the Zacks Consensus Estimate of $5.743 billion but decreased 0.7% from $5.811 billion in the year-ago quarter.The company updated its full-year non-GAAP EPS guidance to the range $10.96-$11.20 from the previous guided range of $10.79-$11.37, owing to hurricane-recovery costs. It also updated its revenue guidance to the range of $22.7-$23 billion from the previous guided range of $22.5-$23 billion. The company’s shares lost around 0.8% during after-hours trading on Oct 25, 2017, after it revised down its guidance.Gilead Sciences reported third-quarter 2017 adjusted earnings of $2.06 per share on Oct 26, 2017, missing the Zacks Consensus Estimate of $2.09 and decreasing more than 25.1% from $2.75 per share in the year-ago quarter. However, the company beat the Zacks Consensus Estimate on the revenue front. The company reported revenues of $6.512 billion, surpassing the Zacks Consensus Estimate of $6.329 billion but decreased more than 13.2% from $7.500 billion in the year-ago quarter.The company updated its full-year revenue guidance to the range of $24.5-$25.5 billion from the previous guided range of $24-$25.5 billion. The company’s shares fell around 3.8% in after-hours trading on Oct 26, 2017, owing to the EPS miss.Biogen Inc reported third-quarter adjusted earnings per share of $6.31 on Oct 24, 2017, surpassing the Zacks Consensus Estimate of $5.70 and increasing 21.6% from $5.19 per share in the year-ago quarter. The company reported revenues of $3.078 billion, surpassing the Zacks Consensus Estimate of $3.036 billion and increasing roughly 4.1% from $2.956 billion in the year-ago quarter.The company’s shares declined 3.9% at market close on Oct 24 due to weaker-than-expected sales of its sclerosis franchise.Alexion Pharmaceuticals Inc reported third-quarter adjusted earnings per share of $1.44 on Oct 26, 2017, surpassing the Zacks Consensus Estimate of $1.33 and increasing roughly 17.1% from $1.23 per share in the year-ago quarter. The company reported revenues of $859 million, which failed to beat the consensus estimate of $867 million but increased roughly 7.5% from $799 million in the year-ago quarter.The company updated its full-year non-GAAP EPS guidance to the range of $5.50-$5.65 and increased its revenue guidance to $3.475-$3.525 billion. The company’s shares declined around 4.5% at market close on Oct 26, 2017, primarily due to the revenue miss.We will now discuss a few ETFs with high exposure to the companies discussed.iShares Nasdaq Biotechnology ETF IBBThis fund seeks to provide exposure to the biotech industry. It has AUM of $9.5 billion and charges a fee of 47 basis points a year. The fund has 8.4% exposure to Amgen, 8.3% to Biogen, 8.0% to Gilead and 3.9% to Alexion (as of Oct 25, 2017). The fund has returned 17.3% in a year and 18.3% year to date (as of Oct 26, 2017). It has a Zacks ETF Rank #3 (Hold) with a High risk outlook.VanEck Vectors Biotech ETF BBHThis fund has AUM of $668.8 million and charges a fee of 35 basis points a year. The fund has 10.0% exposure to Amgen, 9.5% to Gilead, 5.5% to Biogen and 4.2% to Alexion (as of Oct 26, 2017). The fund has returned 18.2% in a year and 17.5% year to date (as of Oct 26, 2017). It has a Zacks ETF Rank #3 with a High risk outlook.ProShares Ultra Nasdaq Biotechnology ETF BIBThis fund has AUM of $486.9 million and charges a fee of 95 basis points a year. The fund has 8.4% exposure to Amgen, 7.9% to Biogen, 7.7% to Gilead and 3.9% to Alexion (as of Sep 30, 2017). The fund has returned 15.75% in the last one year and 41.79% year to date (as of Oct 26, 2017).Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >> Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ISHARES NDQ BIO (IBB): ETF Research Reports PRO-ULT NDQ BIO (BIB): ETF Research Reports VANECK-BIOTECH (BBH): ETF Research Reports Alexion Pharmaceuticals, Inc. (ALXN): Free Stock Analysis Report Gilead Sciences, Inc. (GILD): Free Stock Analysis Report Amgen Inc. (AMGN): Free Stock Analysis Report Biogen Inc. (BIIB): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report