The Fondazione Monte dei Paschi di Siena was created to continue the charitable functions of the bank and to be, until the bailout in 2013, its largest single shareholder.

The basis of its foundation is the Statuto dei Paschi, written in 1419, a law that regulated all activities related to agriculture and pastoralism in Maremma.

[citation needed] On 25 June 1999, Banca Monte dei Paschi di Siena was listed successfully on the Italian Stock Exchange.

[citation needed] After its debut on the Italian Stock Exchange, the bank began an intense phase of commercial and operational expansion.

[16] On 8 November 2007, Monte dei Paschi di Siena announced that it had reached an agreement with Banco Santander to buy Banca Antonveneta for €9 billion[17][18] excluding the subsidiary Interbanca that is owned by the Spanish bank.

From February 2007 to June 2008 Banca MPS sold all the shares (27.839%) in Finsoe, an intermediate holding company of Unipol Group, for €584.8 million.

[21] In the wake of rising yields and declining valuations on Italian government debt in the European sovereign-debt crisis, MPS lost over $2 billion in the first half of 2012, had to recapitalize, and faced restructuring or worse.

The majority owner until the recapitalization, the Fondazione Monte dei Paschi di Siena, long resisted issuing new capital which would dilute its holding.

In September 2012, even after the dilution, the bank "appear[ed] poised" also to give the national government a greater ownership stake in return for more capital.

[25] Estimates of the losses accumulated by the Santorini and Alessandria operations in the period leading up to the derivative contracts range from €500 to €750 million.

On 22 January 2013, the bank's shares lost 5.6% on the stock exchange and Mussari resigned as president of Associazione Bancaria Italiana.

They resolved to grant the Board of Directors the power to increase the share capital by a maximum amount of €4.5 billion to service the exercise of conversion rights of the bank of the Monti bonds.

[31] The firm sparked fresh controversy in 2013 when it was accused of misleading Italy's market regulator in October 2012, shortly before it received a 4.1-billion euro ($5.47 billion) state bailout.

[32] On 29 December 2013, Fondazione Monte dei Paschi di Siena rejected plans for issuing €3 billion worth of new shares, delaying the raising of capital until at least May 2014 and increasing the risk of nationalization.

The court decided that they had conspired to hide Monte dei Pasche's losses of €2bn between 2008 and 2012 by using complicated derivative contracts.

[34] Following an appeal, in May 2022, a Milan appeals court ruling overturned the 2019 conviction of the former executives and the two banks over derivative deals and cancelled the seizures imposed on Deutsche Bank and Nomura Holdings Inc.[35][36] In October 2023, Italy's Supreme Court of Cassation confirmed the acquittals in Monte dei Paschi derivatives case.

Despite issuing €5 billion in shares just four months earlier, the ECB declared the bank unable to withstand a financial catastrophe.

[42] On 6 July 2015, following the Greek bailout referendum, trading in Monte dei Paschi shares was suspended after they fell 5.7%.

[43] Eventually Banca MPS achieved a net profit of €388 million in 2015. but mainly due to the effect of the restatement as a CDS derivative of the Alexandria transaction.

[65] On 3 February 2017 BMPS sold its card business to Istituto Centrale delle Banche Popolari Italiane (ICBPI) for €520 million.

[71][72] On 5 October 2018, BMPS announced the sale of its Belgian subsidiary, Banca Monte Paschi Belgio (BMPB), to a company participated in by funds managed by Warburg Pincus.

[77] With this sale, the Italian government respects the privatisation commitments it made to the EU (during the 2017 bailout of MPS) to reduce its stake below 20% by the end of 2024.

[78] MPS headquarters in the Palazzo Salimbeni in Siena hosts an art collection and a large number of priceless historical documents spanning the centuries of its existence.

The most recent publicly known acquisition of art, a gold-plated panel by Segna di Bonaventura, cost the bank nearly one million Euro.

[79] It is also internationally known as the primary sponsor of Italian basketball club Mens Sana Basket of Siena, currently in Lega A and a regular participant in the Euroleague.

Both international and local groups had raised objections to this expansion on the grounds it would damage the natural beauty of the area, the environment and the attraction of the countryside to tourism.

[83][84][85] The share owned by Fondazione Monte dei Paschi di Siena dropped from over 55% on 31 December 2009[86] to below CONSOB requirement to disclose (<2%) in 2015.

Further research is needed to clarify the degree of this relationship, which involved some exponents of the governing body who were closely connected to Italian Freemasonry.