it's not sound investing practice to fall in love with a stock and buy on the way down. you should remain detached emotionally. sweating it out (...keep some dry powder in case...) isn't sound as well although I admit I am in that boat with this stock now.
swings of 5% could be termed as price fluctuations. But NOV is about to enter bear territory as it is down almost 18% in the last month. That is not a price fluctuation, that is a significant break down. Avoid the stock until it stabilizes because it could easily see a new 52 week low at the rate it is dropping.