  We investigate the waiting-time distribution of the absolute return in the
Korean stock-market index KOSPI. We define the waiting time as a time interval
during which the normalized absolute return remains continuously below a
threshold $r_c$. Through an exponential bin plot, we observe that the
waiting-time distribution shows power-law behavior, $p_f (t) \sim t^{-\beta}$,
for a range of threshold values. The waiting-time distribution has two scaling
regimes, separated by the crossover time $t_c \approx 200$ min. The power-law
exponents of the waiting-time distribution decrease when the return time
$\Delta t$ increases. In the late-time regime, $t > t_c$, the power-law
exponents are independent of the threshold to within the error bars for fixed
return time.
