Rising investor confidence also indicates a rally, and it is perhaps more powerful than any economic indicator because when investors believe something is going to happen (a rally, for example), they tend to take action (purchasing shares in order to profit from expected price increases) that actually turn expectations into reality. Although it is an objective concept, investor sentiment shows through in mathematical measurements such as the put/call ratio, the advance/decline line, IPO activity, and the amount of outstanding margin debt.
Most of the works drivers of the 1950s were amateurs, paid little or nothing, reimbursed their expenses and given bonuses for winning (although there were certainly exceptions, such as the Grand Prix drivers who were brought in for some events). Then in 1960 came arguably the first rallying superstar (and one of the first to be paid to rally full-time), Sweden's Erik Carlsson, driving for Saab.