Coconut oil is almost all saturated fat: solid at room temperature.
But in a small excellent coconut oil study, HDL (healthy) cholesterol improved when coconut oil replaced carbs in one diet, and canola/sunflower oil in another.
This was a scientific study–all meals prepared, weighed, measured, and it lasted only 9 weeks. Not real life. But it’s impressive.
Coconut oil raises HDL because it is primarily myristic and lauric acids. These are saturated fatty acids, which are highly cholesterolemic: they produce high blood levels of cholesterol. This study suggests they produce a much higher level of HDL than LDL, and therefore are worth the intake. For another view, see this review of fat.