Waiting-Time Distribution for Korean Stock-Market Index KOSPI

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 rc. Through an exponential bin plot, we observe that the waiting-time distribution shows power-law behavior, pf (t) ∼ t−β , for a range of threshold values. The waiting-time distribution has two scaling regimes, separated by the crossover time tc ≈ 200 min. The power-law exponents of the waiting-time distribution decrease when the return time ∆t increases. In the late-time regime, t > tc, the power-law exponents are independent of the threshold to within the error bars for fixed return time.