Hello @kartik,

The reverse will involve taking the cumulative sum and then the exponential. Since pd.Series.diff *loses* information, namely the first value in a series, you will need to store and reuse this data:

np.random.seed(0)
s = pd.Series(np.random.random(10))
print(s.values)
# [ 0.5488135 0.71518937 0.60276338 0.54488318 0.4236548 0.64589411
# 0.43758721 0.891773 0.96366276 0.38344152]
t = np.log(s).diff()
t.iat[0] = np.log(s.iat[0])
res = np.exp(t.cumsum())
print(res.values)
# [ 0.5488135 0.71518937 0.60276338 0.54488318 0.4236548 0.64589411
# 0.43758721 0.891773 0.96366276 0.38344152]

Hope this is helpful!!