Ankle weights do not help you run faster or jump higher. To run fast in competition, you have to run fast in practice. Ankle weights slow you down because they interfere with your coordination and make you work much harder to raise your knees.
To jump higher, you have to strengthen your leg muscles in the same way that you use them to jump. Ankle weights strengthen your leg muscles for lifting weights off the ground with your feet. When you jump, you raise your body off the ground. To jump higher, you have to raise your body up against resistance, such as squatting with heavy weights on your shoulders or doing leg presses.
Wearing ankle weights can also increase your chances of injuring yourself by creating a muscle imbalance by strengthening your quad muscles in front of your upper legs more than your hamstrings in the back.