Shares in TomCo Energy Plc (LON:TOM) dipped 12.5% to 3.5p on Tuesday afternoon after its chief executive and major shareholder Christopher Brown handed in his resignation.
Brown - who owns a 19.57% stake in the oilfield developer - wants to step down so he can concentrate on his other business ventures.
He has agreed to stay on until his replacement has been found and TomCo said it was in discussions regarding a new appointment.
Although he's leaving, Brown has also agreed to loan the company ?100,000 for general working capital purposes. The loan will incur interest of 8% per annum, payable in monthly arrears and is fully repayable on 31 March 2019.
Going the other way was Midatech Pharma Plc (LON:MTPH, NASDAQMTP) which jumped after the specialty pharma secured a US$15mln, four-year senior loan facility that will be used to bankroll the clinical development of two promising cancer drug candidates.
The funding has come via MidCap Financial, a middle market finance house, and Midtech has drawn down an initial US$7mln of the facility.
Access to the remainder of the cash will be dependent on MTD201 and MTX110 hitting certain milestones.
Shares are up 18.6% to 42.7p late in afternoon trading on Tuesday.
Oncimmune Holdings PLC (LON:ONC) was the top riser on AIM on Tuesday after the cancer detection firm revealed it expects to start selling to the lucrative Chinese market before 2021.
The company revealed on Tuesday it has signed a framework agreement for an exclusive licence for its EarlyCDT platform with Hong Kong-based R&D and manufacturing group Genostics.
The agreement will see Genostics start the distribution, manufacturing and future development of the EarlyCDT technology in China, starting with the sale of EarlyCDT-Lung within 36 months, "although both parties expect this to be sooner".
Oncimmune said it will receive a royalty of 8% of the gross revenue or ?15.7mln over the first six years, whichever is higher.
After that, the minimum royalty payment drops down to ?5mln (index linked) a year.
EarlyCDT-Lung uses biomarkers for the early detection of lung cancer. It was first launched in the US back in 2012 and has since sold more than 150,000 commercial.
China represents a big market for cancer-focused companies. The disease is the leading cause of death in the country, with an estimated 7,500 people dying from cancer each day.
On top of the agreement, Genostics is paying ?10mln for 6.41mln Oncimmune shares which works out at ?1.56 apiece - a 49% premium to the 105p market closing price on Friday.
Last year was a rough one for The People's operator PLC (LON:TPOP) and its shareholders, and 2018 hasn't got off to a great start either.
Shares in the mobile virtual network operator with a charitable kicker returned to AIM this morning after shareholders voted through a ?2.82mln fundraise at the end of December which keeps the lights on for at least a little while longer.
That fundraising saw shares sold off at 0.1p apiece - a steep discount to the 0.53p closing price on 6 December, the day before the placing was proposed.
Perhaps unsurprisingly then, the share price dived 82.9% to 0.07p on Tuesday. Only a couple of years ago they were changing hands for more than 140p.
Elsewhere, AIM's biggest company ASOS plc (LON:ASC) - valued at ?5.5bn - edged 1.3% higher to ?68.02 after it was upgraded to 'buy' by Deutsche Bank as it carried out a comprehensive review of the retail sector ahead of the post-Christmas reporting season.
Among the bigger boys, FTSE 250 gambling firm GVC Holdings (LON:GVC) saw its shares rise 2.3% to 946p after Barclays analysts gave their backing to its recently-announced ?4bn merger with rival Ladbrokes Coral Group PLC (LON:LCL).
Forestry management company Active Energy Group PLC (LON:AEG) has successfully completed the initial testing of its five tonne per hour CoalSwitch biomass fuel plant in Utah.
Midatech Pharma Plc (LON:MTPH, NASDAQMTP) has secured a US$15mln, four-year senior loan facility that will be used to bankroll the clinical development of two promising cancer drug candidates. The funding has come via MidCap Financial, a middle market finance house, and Midtech has drawn down an initial US$7mln of the facility.
Victoria Oil & Gas plc (LON:VOG) has informed investors of a further extension to its proposed deal for the Bomono project and potential partnership with Bowleven Oil & Gas PLC (LON:BLVN).
Range Resources Ltd (LON:RRL) told investors that its latest well, at the Beach Marcelle field, is "one of the best" the company has drilled in recent years. The well, which has now been put on production, has been flowing at a stabilised rate of 120 barrels of oil per day, the company revealed.
BOS GLOBAL Holdings Ltd (LON:BOS) still needs to augment its board after announcing the appointment of one non-executive director - Will Giles - and the resignation of another, Mark Uren. The company's constitution stipulates that there should be at least three directors and at present it only has two.
Obtala Limited (LON:OBT) has announced the initial funding of a new wholly owned subsidiary, Obtala (Hong Kong) Limited, with the cash earmarked for the financing of the group's timber trading activities.
Ortac Resources Limited (LON:OTC) has appointed Jonathan de Thierry to its board of directors. de Thierry is a trained geologist with 25 years of experience to his name, and one of the founders of Casa Mining, which has now become the central asset in Ortac's portfolio.
Tower Resources PLC (LON:TRP) has issued share warrants to its directors, in lieu of fees, in order to preserve the company's working capital.
Caledonia Mining Corporation PLC has announced a quarterly dividend of US$0.06875 as gold production from the Blanket mine in Zimbabwe continues to throw off cash. Current guidance is for the mine to produce between 54,000 and 56,000 ounces of gold this year.