Any explication why I got this kind of plot? The range of index returns is from 100 to 130. I need help to understand this plot above. The code is simple, but the plot is unclear:
#import needed library
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
#import JPM GBI bound index
df = pd.read_excel('art.xlsx')
df = pd.DataFrame(df)
df.head(8)
plt.plot(df\['Date'\],df\['Index returns'\])
type(df\['Date'\]\[3\])

