You noticed something that a lot of people seem to overlook with their simplified mental model of holes. If holes were "just" missing electrons then a Hall measurement would tell you the charge carriers were negatively charged, but in semiconductors we can see both negative and positive Hall coefficients. So what is going on? Well, holes are more than just missing electrons, and dont settle for answers from people who insist they are. (There are many such people. In my experience, holes are widely misunderstood. I blame professors who tell their students that holes are like a bubble in water. Its a horrible analogy.)
There are a few counterintuative effects in play. Semiconductors have two "bands" of interest where there exist allowed energy states with a band gap in between which has no allowed states. What makes semiconductors interesting is that both of these bands can have a non-negligible contribution to current.
The energy-momentum (E-k) relationship for each band defines the allowable states, and actually defines the bands themselves. At the bottom of the conduction band things behave in a reasonable intuative way, but at the top of a band, things get weird.
First, lets talk about filled bands. 531
A filled band contributes exactly zero current. This is the first counterintuative thing we have. This is because of symmetry within the bands. For every state moving in one direction, you have another state moving in the opposite direction, and these exactly cancel out. This means when we have a nearly filled band, such as the valence band, we find it easier to talk about the missing states, and compute total current as the current from a filled band (which is 0) minus whatever those empty states would have contributed had they been filled.
Okay, but we still have electrons, right? Yes and no. The E-k relationship at the top of a band is approximately an upside down parabola. This means those states have a negative effective mass. This makes them move the "wrong way" under an electric field. This is another one of those counterintuative things about semiconductors. Add up these effects and you have particles that act like they have a positive charge.
So while you may decide its easier to think about electrons with negative effective mass and counting up all the contributions from a mostly filled band, everyone else likes to think about "holes". They act exactly like positively charged particles and it will serve you well to just accept them as particles that are equally as real as electrons. 531