According to the last update from Kantar, Sainsbury’s market share last month declined by 0.2 percentage points to 15.9% as it struggles, along with the other big three, against the discounters.
But it is the integration of Argos that catches Jefferies' attention, which rates shares as 'hold'.
"We remain unsure if Argos will prove a longer term lift to JS' store economics, or whether it risks becoming an incremental distraction to a challenged core business," said analyst James Grzinic.
He notes that, on one hand, it has successfully accelerated non-food growth but the store's food performance looks to have been on a deteriorating trend in 2016.
The broker also reckons that UK consumer outlook may represent an incremental challenge in the months ahead.
Investment bank Credit Suisse also looks at the stock today, but is far more upbeat. It repeats an 'outperform' stance and pumps up the target price to 315p from 290p.
The same broker also lifts Tesco's (LON:TSCO) target price to 130p from 115p and repeats an 'underperform' stance. Morrison's (LON:MRW) is rated 'neutral' by the broker, but it lifts the target to 20 p to 200p.
Meanwhile, heavyweight Goldman Sachs gets its teeth into the banking sector, and downgrades Lloyds Banking Group (LON:LLOY) down to 'sell;' from 'neutral' and moves challenger bank Metro (LON:MTRO) down to 'sell' also from 'neutral' previously.