Saudi Aramco may have debuted on the country's own stock exchange last Monday, but investing it the world's most highly-valued company has not yet become available to American market investors. As of last Thursday, Aramco is valued at $2 trillion, which is nearly double Apple (AAPL  ), the oil giant's closest competitor. An easy way to invest before Aramco's stock opens to global trade is through iShares MSCI Saudi Arabia ETF (KSA  ), which is the only single-country ETF for Saudi stocks.

ETFs on the move last week:

The SDPR S&P Biotech ETF (XBI  ) has reached record highs last week, capping off on Friday with a fresh 52-week high. The biotechnology sector has been boosted by the mergers of Merck's $2.7 billion purchase of cancer drugmaker ArQule, Sanofi's $2.5 billion buy of Synthorx, which specializes in cancer and autoimmune disorder therapies, and Roche's buy of $4.3 billion take over offer of the gene therapy developer Spark Therapeutics. The Biotech ETF year-to-date gains have more than doubled the gains for the HealthCare Sector (XLV  ).

VanEck Vectors Semiconductor ETF (SMH  ) and iShares PHLX Semiconductor ETF (SOXX  ) have also reached fresh highs to close out the week as news of China and U.S. nearing trade deal drove stocks like Apple (AAPL  ) to new heights. A more favorable trade deal with China will only bring greater gains as Morgan Stanley (MS  ) equity strategists stating that "semiconductor and semiconductor equipment companies have the highest revenue exposure to China at 52%."

Energy Select Sector SPDR Fund (XLE  ) continues to underperform for the year, though analysts predict that this is the perfect time to buy due to the energy sector's nature of being highly cyclical form its profitability being floated by its dependence on supply and demand. XLE's shares are also mostly companies in competitive positions like Chevron (CVX  ), who is writing down as much as $11 billion worth of assets.

United States Oil Fund's (USO  ) price outlook is looking better in recent markets, with the ETF's year-to-date growth encroaching on +30%. However, crude oil futures have pulled back from three-month highs after U.S. government data showed an unexpected increase in its domestic supplies.