The tic marks at at the instants of permitted change and are actually marked by a synchronized clock signal generated in the hardware but not sent over the external cable. Suppose it has 4 possible outcomes, each represented by a unique voltage level. Here the bit rate is double the baud rate. In other words 3000 baud results in 6000 bps. The above example is overly simple.
Real examples are more complicated but based on the same idea.
Thus, when 2 or more bits are encoded per baud, the bps rate exceeds the baud rate. Because of the bandwidth limitations on voice-grade phone lines, baud rates greater than 2400 are harder to achieve, and only work under conditions of good phone line quality. Well, back when antique low speed modems were high speed modems, the bps rate actually did equal the baud rate. One bit would be encoded per phase change. People would use bps and baud interchangeably, because they were the same number.