matplotlibでScatterを追加したが、エラーが出てしまう。

matplotlibでScatterを追加したが、エラーが出てしまいます。
コード

# plot the Finonacci levesl
plt.figure(figsize=(18.495,14.25))
plt.plot(new_df.index, new_df['Close'],color='black')
plt.scatter(new_df.index, new_df['Buy_Signal_Price'], color='green', alpha=1)
# plt.scatter(new_df.index, new_df['Sell_Signal_Price'], color='red', alpha=1)

plt.axhline(max_price, linestyle='--', alpha=0.5,color='green')
plt.axhline(fist_level, linestyle='--', alpha=0.5,color='green')
plt.axhline(secon_level, linestyle='--', alpha=0.5,color='green')
plt.axhline(third_level, linestyle='--', alpha=0.5,color='green')
plt.axhline(fourth_level, linestyle='--', alpha=0.5,color='green')
plt.axhline(fifth_level, linestyle='--', alpha=0.5,color='green')
plt.axhline(min_price, linestyle='--', alpha=0.5,color='green')

plt.ylabel('Close Price in USD')
plt.xlabel('Date')
plt.xticks(rotation=45)
plt.show()

エラー

TypeError                                 Traceback (most recent call last)
<ipython-input-12-e02e414dc72b> in <module>
      5 plt.figure(figsize=(18.495,14.25))
      6 plt.plot(new_df.index, new_df['Close'],color='black')
----> 7 plt.scatter(new_df.index, new_df['Buy_Signal_Price'], color='green', alpha=1)
      8 # plt.scatter(new_df.index, new_df['Sell_Signal_Price'], color='red', alpha=1)
      9 

~\anaconda3\envs\crypto\lib\site-packages\matplotlib\pyplot.py in scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, hold, data, **kwargs)
   3376                          vmin=vmin, vmax=vmax, alpha=alpha,
   3377                          linewidths=linewidths, verts=verts,
-> 3378                          edgecolors=edgecolors, data=data, **kwargs)
   3379     finally:
   3380         ax._hold = washold

~\anaconda3\envs\crypto\lib\site-packages\matplotlib\__init__.py in inner(ax, *args, **kwargs)
   1715                     warnings.warn(msg % (label_namer, func.__name__),
   1716                                   RuntimeWarning, stacklevel=2)
-> 1717             return func(ax, *args, **kwargs)
   1718         pre_doc = inner.__doc__
   1719         if pre_doc is None:

~\anaconda3\envs\crypto\lib\site-packages\matplotlib\axes\_axes.py in scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, **kwargs)
   4021             linewidths = rcParams['lines.linewidth']
   4022 
-> 4023         offsets = np.column_stack([x, y])
   4024 
   4025         collection = mcoll.PathCollection(

<__array_function__ internals> in column_stack(*args, **kwargs)

~\anaconda3\envs\crypto\lib\site-packages\numpy\lib\shape_base.py in column_stack(tup)
    654             arr = array(arr, copy=False, subok=True, ndmin=2).T
    655         arrays.append(arr)
--> 656     return _nx.concatenate(arrays, 1)
    657 
    658 

<__array_function__ internals> in concatenate(*args, **kwargs)

TypeError: invalid type promotion

元データ