Why does this random value has 25/75 distribution instead of 50/50?

Edit: so basically what I'm trying to write is a 1 bit hash for double.

I want to map a double to true or false with 50/50 chance. For that I wrote code that picks some random numbers (just as an example, I want to use this on data with regularities and still get 50/50 result), checks their last bit and increments y if it is 1, or n if it is 0. However, this code constantly results in 25% y and 75% n. Why is it not 50/50? And why such a weird, but straight-forward (1/3) distribution?

public class DoubleToBoolean {
    @Test
    public void test() {

        int y = 0;
        int n = 0;
        Random r = new Random();
        for (int i = 0; i < 1000000; i++) {
            double randomValue = r.nextDouble();
            long lastBit = Double.doubleToLongBits(randomValue) & 1;
            if (lastBit == 1) {
                y++;
            } else {
                n++;
            }
        }
        System.out.println(y + " " + n);
    }
}

Example output:

250167 749833