In my short term experience with these BDCs and CLO type investments, it is not unusual to see these types of sell offs. I've seen them before in stocks like NEWT and GAIN, not to mention ECC and OXLC. The question is whether there is any fire with that smoke or if it's just some institution bailing out because they made their money and are moving on to some other bright shiny object. While not as severe a selloff, both GAIN and NEWT have been trending down and are dipping below their 50 dma. I think you will see OFS bounce here off its 200 dma as that is usually a support level, at least temporarily. In fact as I wrote this, I noticed a 16 cent bounce and the volume appears to be low, which I interpret as the selling is not accelerating. On balance volume (OBV) is still going up.
There are 2 ways to play this action. Add some here on the belief that this is noise and the 200 dma was tested and held. The stock is slightly oversold. Your belief in technicals has to be strong and you have to have the correct interpretation of them.
Or you could wait until they report earnings to see if there was any miss. While you might miss an upmove if the earnings come in, it's not like the stock is going to run up 4 points on a beat.
You could also monitor the reports of other BDCs in the same sector for info on spreads and NAVs etc. As I remember, OFS is trading below book, so that gives some cushion assuming the book hasn't deteriorated.
Maybe some of the money moved out of OFS and into ORCC.