Analyze the sentiment expressed in the tweet. Is it positive, negative, or neutral? Explain the sentiment in relation to the stock mentioned.
TWEET: "@AskAmex @AmericanExpress Yes.  I added my son this summer.  5000 points. After 500$ spend Activated the card Augus… https://t.co/rriaOSvbFA" STOCK: nan DATE: nan
Sentiment: (Provide sentiment here)
Explanation: The tweet sentiment is related to the stock mentioned, and it's important to interpret the context. The LSTM polarity score is nan and the TextBlob polarity score is nan.