After a seven-week winning streak, the ASX delivered its first weekly loss in a shortened yet eventful trading week.

Investors weighed up a range of matters including long-awaited fiscal stimulus in the US, the NSW COVID cluster, Brexit negotiations and the threat of a more virulent strain of COVID overseas.

The ASX 200 finished the week 10.7 points lower than last Friday on 6,664.80.

Which shares excelled?

Credit Corp (ASX: CCP) was one of the week strongest performers, leaping 18.5% on a profit upgrade following an acquisition. The company is acquiring the Australian ledger book of embattled peer Collection House (ASX: CLH), with the Purchased Debt Ledgers (PDL) book set to be acquired well below its face value at an approximate outlay of $150 million. On the back of the acquisition, Credit Corp has increased its Net Profit after Tax (NPAT) forecast for FY21 by $10 million.Acquisition news also spurred on Challenger (ASX: CGF), which gained 8.5% since last Friday. The investment manager is acquiring MyLife MyFinance, a customer savings and loan bank that is a subsidiary of Catholic Super, for $35 million. Through the acquisition, Challenger will effectively compete in the sizeable term deposit market, as it will gain access to an authorised deposit-taking institution (ADI) licence.On the back of a buoyant iron ore price, Mineral Resources (ASX: MIN) also had a bumper week. With the commodity at one stage trading as high as US$176/tonne, interest in iron ore stocks has reached fever pitch of late, with shares in MIN proving no exception. Since the end of October the stock is up more than 40%. Likewise, another resource stock on fire lately has been Pilbara Minerals (ASX: PLS), with upbeat sentiment helping the lithium producer gain 8.6% this week.Finally, after disappointing performances last week, there were stronger results from the likes of A2 Milk (ASX: A2M) and Yancoal Australia (ASX: YAL), with investors seemingly prepared to buy the dip.

Which shares dragged on the market?

A disappointing trading update from AGL Energy (ASX: AGL) sent shareholders racing to the exits, with the stock dipping 8.8% this week. The company slashed its profit forecast for FY21 following an incident with a transformer at its Liddell Power Station last week, which is expected to leave the facility offline for several months. At the mid-point of its guidance, underlying profit after tax is expected to be $40 million lower than previously advised.WiseTech Global (ASX: WTC) came in for a tough time this week after it was the subject of a new short report. The research house behind the report took aim at WiseTech acquisition history, questioning the strength and validity of these purchases and their contribution to the company. Understandably, WiseTech were quick to respond, arguing the analysts in question lacked understanding of the firm acquisition strategy and the risk, cost and time involved in developing technology internally versus acquiring it.Amid international delivery delays to as many as 12 of its shipments, Electro Optic Systems (ASX: EOS) was forced to revise its revenue and earnings guidance to the market. While the orders will still be executed, the timing has been pushed from 2H FY20 into FY21. Nonetheless, despite management indicating there would be no impact to cash flow for either financial year, investors erred on the side of caution and the stock retreated 6% over the week.Elsewhere, there were modest retraces in shares of EML Payments (ASX: EML) and Zip Co (ASX: Z1P), with the former dropping below its capital raising price, and otherwise bucking the trend of segment leader Afterpay (ASX: APT), which posted a healthy gain this week.However, they weren't alone in being the only underperformers from their industry, with goldies Newcrest Mining (ASX: NCM), Ramelius Resources (ASX: RMS) and Silver Lake Resources (ASX: SLR) falling more than their peers.

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