No. You will need to submit your bank statements for at least a duration of 6 months.
Check this link: https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/permanent-residence/express-entry/applications-received-on-after-january-1-2016-completeness-check.html
Under Proof of Funds section in the above link, you will see that IRCC requires the 'average balance for 6 months'. This enables the assessing officer to see if any major funds have been deposited to bulk up the balance in the last 6 months or that the balance has been relatively stable and exceeds the minimum funds required by IRCC. This in no way means that no deposits are permitted, but that if a legitimate deposit is seen, you should explain it in your letter of explanation.
Most banks do not provide the 'average balance' figure in the proof of funds letter so its safer to provide bank statements for the last 6 months so that the assessing officer can review it himself.
Sure. Go ahead and provide a statement for four months. Make sure you clarify that the source of funds with which you opened the account in your letter of explanation.