Is the value at risk exceeded as often as it should be? The likelihood ratio test of Kupiec (1995) compares the share of days with a loss beyond it with the share it promises, such as 5%.
Examples
golemstockindices:::kupiec_test(c(13, 30), days = 252, p = 0.05)
#> [1] 9.084112e-01 1.658095e-05