And what is that telling us? Well, it's telling us at least for this sample, this one time that we sampled the random variables x and y, x was above its expected value when y was below its expected value. And if we kept doing this, let's say for the entire population this happened, then it would make sense that they have a negative covariance. When one goes up, the other one goes down. When one goes down, the other one goes up. If they both go up together, they would have a positive variance. Or if they both go down together, the degree to which they do it together would tell you the magnitude of the covariance.