I bought DOW when it was the 'falling knife' - bad error, swore...

I bought DOW when it was the 'falling knife' - bad error, swore I wouldn't do that again - but now it is so low - it has to be good long term buying ?? - IF NOT FOR THE RISK that there is more to this MASSIVE FALL ie: COMPANY in MUCH WORSE SHAPE. I have bought companies that have gone belly up before when I thought they were bargin basement prices (Pasminco / Sons of Gwalia) ... I am very tempted to buy some more - but already have taken a big hit. I guess I am thinking was many on this thread are - SHOULD I / SHOULDN'T I .... this market is doing my head in. cheers ikhutch.