Credit Suisse Re-rating

I have learned through experience not to follow broker ratings however any comments on this. NST are a key investment in my PF so just putting this out to comments, Credit Suisse say:

"First-half net profit beat Credit Suisse estimates because of toll treatment contributions that were not discernible from the quarterly reports.FY20 guidance is unchanged and a stronger second half is expected.? Underperform rating and $10.30 target maintained.Sector: Materials.Target price is $10.30.Current Price is $13.67. Difference: ($3.37) – (brackets indicate current price is over target). If NST meets the Credit Suisse target it will return approximately -33% (excluding dividends, fees and charges – negative figures indicate an expected loss)."