There are two main types of HSX securities and they each have their own rules.
Moviestock prices are based on how much box office traders think a movie will do during its first 4 weekends of wide release or first 12 weekends of limited release. 1 mill box office = $1 moviestock price. A $12 moviestock = 12 mill box office.
The first weekend that a movie is released wide there is an "adjust". HSX price changes the moviestock price at the end of the weekend using the formula: "(Fri - Sun) * 2.7" HSX has found mathmatically that most movies released wide average 2.7 times their opening weekends during their first 4 weekends. So you basically make an investment for the opening weekend and then after the price adjust you adjust your investment based on whether you think a movie will have "legs" (do more than the 2.7 - usually animation and kids movies) or be "frontloaded" (most people who wanted to see the movie came the first weekend and the movie ends up below the 2.7 - usually horror movies)
Movie ABC you expect to make $10 over its opening weekend.... $10 * 2.7 = $27 adjust (you are investing opening weekend expecting it to adjust to this price... if the current price is below $27 then you might want to invest long to make a profit... if the current price is above this amount you might want to invest short to make a profit)
Starbonds are based on the average of a starbond's last 5 projects. Starbonds are adjusted the day after a movie that they are "attached" to is delisted (after its 4 weekends). You add the box office of the new movie with the box office of the last 4 movies and divide by 5 for the "adjust" (new price). This is the basics of how it works (there are many exceptions and there are weird situations but this is the basic).
Starbond XYZ has $100, $100, $100, $100, $100 = $500 / 5 = $100 TAG (worth/price)
Starbond XYZ is in a movie that makes $50. This is how the price would change:
Starbond XYZ... $100, $100, $100, $100, $50 = $450 / 5 = $90 TAG (new price)