The market showed some volatility last week. It increased early in the week and then fell significantly during the latter half of the week. Oil prices reacted much the same way, falling under $100 per barrel on Friday. This served to hurt the share prices of many offshore drilling companies over the course of the week. As usual though, they each reacted in a different way to the overall market movement.

**SeaDrill** (NYSE:SDRL) opened on Monday, April 30 at $38.48. The stock closed at $37.45 in after hours trading on Friday, May 4. This gives the stock a loss of $1.03 or 2.68% this week. SeaDrill opened at $37.00 on April 9, 2012. This gives the stock a four-week gain of $0.45 per share or 1.22%.

**SDRL 5-Day Chart**

* charts*

Source: Fidelity Investments

**SDRL 4-Week Chart**

Source: Fidelity Investments

**Ensco** (NYSE:ESV) opened at $54.20 on Monday, April 30. The stock closed at $51.42 in after hours trading on Friday, May 4. This gives the stock a loss of $2.78 or 5.41% over the week. This completely erases the gains that Ensco saw last week. The stock opened at $51.63 on April 9. The stock thus had a loss of $0.21 or 0.41% over the four-week period.

**ESV 5-Day Chart**

Source: Fidelity Investments

**ESV 4-Week Chart**

Source: Fidelity Investments

**Transocean** (NYSE:RIG) opened at $49.93 on Monday, April 30. The stock closed at $47.95 in after hours trading on Friday, May 6. This gives the stock a loss of $1.98 or 4.13% this week. The stock opened at $50.45 on April 9. This gives Transocean a loss of $2.50 or 5.00% over the four-week period.

**RIG 5-Day Chart**

Source: Fidelity Investments

**RIG 4-Week Chart**

Source: Fidelity Investments

**Diamond Offshore** (NYSE:DO) opened at $67.84 on Monday, April 30. The stock closed at $65.11 in after hours trading on Friday, May 4. This gives the stock a loss of $2.73 per share or 4.02% for the week. The stock opened at $64.82 on Monday, April 9. The stock thus had a four-week gain of $0.29 per share or 0.45%.

**DO 5-Day Chart**

Source: Fidelity Investments

**DO 4-Week Chart**

Source: Fidelity Investments

**Atwood Oceanics** (NYSE:ATW) opened at $43.64 on Monday, April 30. The stock closed at $42.15 in after hours trading on Friday, May 4. This gives the stock a loss of $1.49 per share or 3.41% for the week. Atwood opened at $43.51 on April 9. Thus, shareholders in the company suffered a loss of $1.36 or 3.13% over the four-week period.

**ATW 5-Day Chart**

Source: Fidelity Investments

**ATW 4-Week Chart**

Source: Fidelity Investments

**Noble Corp** (NYSE:NE) opened the week at $37.74 on April 30, 2012. The stock closed at $36.78 in after hours trading on Friday, May 4. This gives the stock a loss of $0.96 or 2.54% for the week. Noble opened at $35.64 on April 9, 2012. Thus, the stock had a four week gain of $1.14 or 3.19% over the four-week period.

**NE 5-Day Chart**

**NE 4-Week Chart**

Source: Fidelity Investments

Noble was the best performer this week with SeaDrill in a very close second. Ensco was this week's worst performer but all six of the stocks punished investors with capital losses over the last week. Noble proved to be the best performing stock over the four-week period. Of these six stocks, only SeaDrill, Noble, and Diamond Offshore delivered a positive performance over the four-week period. Transocean was the worst performer over the trailing four week period with none of the others anywhere close.

Overall, the losses that the sector suffered over the last week has improved the investment opportunities here. The offshore drilling industry has very strong fundamentals and strong growth prospects going forward.

**Disclosure: **I am long SDRL.